Engagement on the verge of ending...

I normally don't post things openly like this on the internet, but I need some help. I apologize in advance for this taking so long.

My fiancé and I have been together for almost 4 and a half years, and have been engaged for 9 months. I'm going to give you some background info on us:

We knew each other from high-school and when we started talking again (as friends) I was just out of a bad 8 yr, very on and off relationship. I was taking the time I needed for myself (and my daughter from a previous relationship), but he was very persistent. We talked for about 8 months before I decided to finally start spending time with him. Eventually we started dating and it was a very rocky start. for about a year we had our ups and downs and actually had broken up for a brief period of time during then. After then I had realized what I wanted and I had stuck with him. Things were good until eventually things started happening to make me think otherwise. He would get mad if I wanted to go somewhere on the weekend, because he had a trailer he was paying for and didn't want to miss any time away, and he got very busy with work and didn't get to see us that often...then he mentioned that him moving in with my daughter and I might make things better. This was put on hold for a while, because I had to clean my place up (spring cleaning if you will) to make room for him and his things. But I wasn't moving at the speed he liked and he would cause arguments over it. And not arguments, full blown out craziness. So then one day we thought we'd go on vacation with some friends because he needed the vacation from work, and it would give us some nice time away with each other. So we went away, and the following night that we got there, he proposed to me infront of all his friends there. I said yes obviously, because I loved him, and I want to marry him and he was happy. I had this notion that things would look up from then. So then we got back after a great vacation with each other, but we kept getting into fights over stupid little things because things don't go his way, or he's stressed out, or something is bothering or annoying him and he gets mad. Then I get upset at him for getting so mad over it and being rude, and then he gets mad at me for getting mad at him and turning it around saying the only reason why he got mad was because I got mad at him over nothing....it doesn't make sense. He also talks down to me because he gets mad, thinking he's trying to encourage me to do something when really he's not...he just hurts my feelings.

So more recently, he's been very immersed in his work and he's been trying to keep it afloat but its going to end up going under. He's seen it coming for a bit now. Just after many talks and arguments and trying to compromise I'm at my wits end. He just hasn't changed and things are getting worse for us. I haven't wanted to finish my place for him to move in because I don't even want him to move in now, not if we're constantly fighting and can't work things out...it's only going to get worse. He's just very selfish and stubborn. He doesn't think about the needs of others and only does things if he wants to, or if it will benefit him in some way. He tries to manipulate your thinking into believing he is right and you're wrong. I've just been feeling so distant from him and have been seeing a side of him come out that I don't like. It's like he doesn't care about anything anymore. I've threatened leaving several times to him, and I just haven't been feeling happy and it feels I'm in this relationship with someone I hardly know anymore.

We got into an argument last night because I was sick and he had called after work and had asked me if I wanted anything - he would bring it to me. So I said no, I can't really think of anything at the moment. So he said okay. I called him back shortly after that because I realized I needed water and I was thirsty and not feeling well enough to go out. So I asked him if he could pick me up a case and I'd pay him when he got back. He said sure (he seemed to be in a decent mood then). He showed up an hour and a half later, and said that he missed it because the store is closed. I told him of another one that way open and he asked until what time, so I told him. He seemed disgruntled and let out a big lengthy sigh and said fine. He got into his truck and went. When he came back, he was walking very quickly and seemed very distant and just in a mood. I asked him if he was in a hurry, and he snapped at me and said he had so much to do and he hasn't even had time for himself yet, he was going around being a slave for everyone else today. I got upset and I said excuse me for being such a burden. He offered to do it for me and he had no problems then...and then its just escalated into an argument. He tried apologizing afterward, but its like enough is enough. Regardless of your day, you still should treat the people who should mean the most to you like shit. Especially when they are sick and not feeling well. I tried to tell him I had enough and I couldn't do it with him anymore. I told him that we're just two different people and that I'm not happy anymore. I couldn't handle the stress of all the fighting and his temper. I told him I wasn't going to be his punching bag anymore...and that I was done. He wouldn't listen to me. He kept arguing with me and telling me he'd change and telling me what he's going through and I told him how i've been feeling this whole time since he's been wrapped up in work and he just doesn't get it. He keeps saying he'll change, he'll change. But I told him I understand he doesn't want to end things...thats what he wants. But what if I wanted to end things? What if thats what I wanted? But he still didn't understand that. I was on the phone with him that night arguing and my temperature was spiking and I was getting a fever and really not feeling well and I had told him I wanted to go and get some rest and I didn't want to talk anymore, and he still kept me on the phone for over an hour after that. He just doesn't think. And then today, he calls me and speaks to me like nothing even happened...

I don't know what to do anymore...I'm at a loss for words. He doesn't listen to me when I give him advice or tell him our relationship is in turmoil...and he doesn't listen when I tell him we need to go our separate ways. I feel myself and my daughter deserve better. She loves him, I know she does but its not good for us to be fighting like that around her either. Its only going to get worse and I left my previous relationship because of it. He has a temper and can't control it. I love him too, but I honestly feel no connection with him anymore. Someone already told us that they didn't see the "passion" between us. And I was asked if I was actually going to marry him, because he's selfish and needs to grow up. I'm starting to really agree with them. He's become this person that I feel I don't even know anymore. Please give me some advice on what I should do...I know what I feel I want to do, but he's not letting me leave...