Slip ups on exercising due to insecurity

Okay, so I have been taking losing weight very seriously lately. Bit of a background so you can get a better idea. Looking back, I had always been a yo-yo dieter/exerciser. I had always been worried about my weight, but I had not taken much action in high school, but started to the summer I turned eighteen. Starting kind of young, I had made my fair share of mistakes. The first one was finding this weird exercise that made me drop the pounds very quickly. It felt good at the time, but dropping the pounds so fast isn't such a good thing. You would have to stick with whatever you were doing no matter what. If I got sick, oh well, I would gain a little bit back due to not exercising for that day. I had to share a crowded hotel room during like a three or four day week, and couldn't get enough privacy to exercise, so I started noticing my stomach getting bigger after like three days (add one extra day for the 7 hour drive). Then after the vacation, I started back up and lost the bit of "tummy" I had gained back. I was able to keep doing the weird exercise during my first semester of college, and I looked good. Then, the second semester, I took a very frustrating class. Science is NOT my best subject, and I had to spend extra time studying it, which caused a lot of stress, and my exercising failed. I gained everything back then some. That summer didn't leave much time for exercising, so I tried dieting. That actually did not work as well as I thought it would. I didn't lose, and all it did was frustrate me enough to crave everything, so I would hide and eat. So fast forward to the summer after. I decided I would exercise again, and did the weird exercise again. Not such a good idea since if you lose weight really fast, you gain it back faster. Okay, so my mom got me into Richard Simmons (Yeah, make fun all you want, but I had my doubt about his videos, too, but love his work outs now. The trick is to put more into it than the people on the screen do), and I decided (and still do believe) that losing weight slowly was better since you can maintain it easier. So that summer and the semester following, I maintained exercising. But doing it during the day causes stress since you feel like you have to make time for it in the middle of your daily activities. Fast forward to following summer after that semester, I researched exercising first thing in the morning and decided that it was right for me (I still prefer and love to exercise first thing in the morning). Everything was going well until about a couple of months ago. I started slipping up way too often. I had slipped up before but I the most before was like two at a time. Recently, it has gotten worse. The first recent time was during a vacation I took last December, but I kind of let that go since it was just one week, and I got right back on track after vacation. The second time was during my last Spring Break, but let it go since I got right back on track. Okay, now I have transferred out of junior college and am now at a university, so I went from semesters to quarters. Last Spring quarter, I had a month slip up. I felt bad about it, but got right back on track. The summer was fine, and I kept on track during the summer. Now this quarter has been a different story. I haven't been exercising as much as usual (which is 3 days a week for 40 minutes), but I have been taking my green coffee bean extract that I have been taking since a year ago, and yes I do have the right kinds of green coffee bean extract, and they have been helping me maintain the weight I have lost, even with my slip ups. I have lost weight and have been successful with my weight loss journey since I went from being over 200 lbs to now being 175.5 lbs. Not my goal weight, but hey, I'm closer to it now than I was at over 200 lbs. I felt proud of myself after I found out exactly how much I lost. I didn't know before since our scale is broken and I found out my current weight at the doctor's at the beginning of November. Now even though I have been proud of myself, I didn't get right back on track. For like the last month or so, I have been only exercising like 1 day a week. I have been lazy, and going through my slip up period. Another part of it is my boyfriend. My weight has made me really insecure, and I always think that if I go to bed early to wake up early the next morning, he'll talk to other girls and forget about me. Irrational, I know, but this is the kind of thinking that has been making me slip up since I think that he may talk to other girls or whatever if I don't stay up and talk to him. That I don't know what he's doing when I'm asleep and he stays up until like midnight. But I know that's absurd since he is a great and loving guy, and has shown me over and over that he would never do anything to hurt me. And I know he wouldn't, but I have always been so insecure that I always think he'll leave me for someone else who is better. He has told me over and over that he loves me, and that he thinks I'm perfect in every way and only wants me, and doesn't care about anybody else. He wants to spend the rest of his life with me, and we plan to move in together after we both finish college (which should be in like a year or so). Even after all of this, I still worry that he will leave me, which is why I stay up talking to him instead of going to bed early so I can wake up early the next morning to exercise. I have decided to get back on track since I really want to make working out a part of my daily routine for life and not just do it until I reach my goal weight. One thing that has made me feel better about going to bed early is that my boyfriend and I are now doing this new thing where whenever it's time for me to go to bed, he'll call me and keep me company while I fall asleep. We stay on the phone all night. The phone will automatically hang up after 4 hours, and every time I wake up at like 1 in the morning to discover we're no longer connected, I'll look and every time, the conversation has cut off one minute before 4 hours total. I'll even call him back, and he'll answer and we'll fall asleep on the phone together again. So how can I get back on track for good? Also, how can I stop being so insecure to the point of me giving up a healthy routine to make sure my boyfriend doesn't leave or cheat on me, even though I know for a fact he'd never do that?

A bit of formatting would be nice here.
Also if he will date a woman who weighs 175 to 200, then body type is probably not a problem for him.
girl listen - the man likes you. He ain't gonna go off and find someone in the time you are sleeping or sweating at the gym.

Getting on track -
Getting TO the gym is the hardest part. Once there though, you need to focus so that the ONLY thing that matters is you and the sweat.

Say it takes three hours to drive to the gym, work out, tan, shower, head home, pick up phone. he isn't gonna have much time to cheat now is he? Unless he is on his cell phone and hanging out with his other G/F while talking on the phone with you. KIDDING, KIDDING!

Man, four hours a day on the phone? I dont talk to my sweety for four hours on the phone in a week.