How do I know if he's serious?

I'll try to keep it short as possible, but I want to make sure I get a couple points across. Sorry it's all "he said, then I said, blahblahblah". I can tell I'm probably over analyzing it, and sound like an idiot, but I really need someone's take on this and I really, really appreciate it. :) It's not the first time I've posted on here and I really appreciate any thoughts you guys have.
My ex boyfriend and I (both 20) broke up about a month and a half ago after only dating for a month. <--major reason I'm on the fence about taking him back
He said that we weren't working out and that he needed to be alone for a while to figure out all the "drama" in his life. His parents were being horrible, his best friend was sleeping with his ex girlfriends and cheating on them, wasn't getting paid though he was working all the time and trying to pay for school, new depression meds not helping, etc. I know someone's going to tell me that this is more than I should be willing to deal with, but I know for a fact that a lot of this is cleared up. He felt at the time that he was under pressure from all angles and that starting a new relationship was too much. He kept saying that he just needed to be alone. However, he mentioned something about his ex (who was cheated on by the roommate/best friend) being over and upset and he didn't want something to happen, which put a whole new spin on everything.
Sort of an important side note (sorry if it's TMI): the only thing we had ever not agreed on was sex. He had never had to wait with the girls he has been with, while I wanted to wait until I felt like we were pretty stable (a few months). He never pressured me about it, but he was definitely always willing to
go as far as I would let him. We were...ahem... starting to mess around, just not going all the way. I knew he was frustrated, but we talked about a couple times and he seemed to understand, saying he knew it was stupid to compare what happened with his exs to me. But sometimes it seemed like he was putting too much importance on it. I remember saying "how are we supposed to know if we work together for real if we spend all our time making out?" lol

Only the day after dumping me he contacted me saying that he still liked me. He backed off when I reminded him that I would only consider taking him back if he was actually willing and able to be in a good relationship. He agreed and said that that was why he wasn't going there yet. Then like a week later he told me he missed me, the next day saying he had been miserable. He said he was over his emotional breakdown and asking if he could be with me again. Of course, I was skeptical the whole time because of the ex girlfriend thing (thinking maybe he had tried to rekindle that and it didn't work), so I brushed him off saying that we could talk when he had put himself together. I figured it would be pretty cut and dry, if all he wanted was to not be alone he would give up on me and find somebody else. I only contacted him once since the break up to say I was ok with being friends since he asked (I'll admit, I broke, lol) and we started talking again like close friends, though he kept trying to flirt.

So I didn't hear from him for a couple of weeks, then a few days ago he contacted me saying he liked me and I was pretty, haha. I brushed him off again. Then the next day, he said he missed cuddling with me although he was never comfortable and basically said he wasn't over me even though he knew he was the one to mess it all up. I asked what he wanted out of me, he said he just wanted a redo of everything that had happened and to be a part of my life. He wants to start dating again but at a slower pace, "not so sexual". I burst out laughing of course (my I told you so moment). I jokingly asked if he had had a spiritual awakening or something and said I would need to think about it. He just said "yes I have, and yes that's fine" and we said goodnight.

So now I don't know what to do. There are so many little facets to consider and I'm an over analyzer, like many of us on this site ;) I was pretty convinced that he just lost interest and was looking for something different then what I had to offer, but he's been so persistent about it... not to mention the "not so sexual" thing, which threw me for a loop. I hadn't even brought it up. I've left him hanging like four times now, and he still keeps saying he misses me and wants to get back together, how do I know when he's actually being serious? One one hand I think "hey we were only together a month, maybe it wasn't a good enough go to really know if we work" and then I think "it was only a month and he couldn't handle it, it's just gonna happen again".

ugh. men.

It seems to me that he is confused at what he wants out of a relationship. It also looks like that he is trying to find that certain element within a person that will make him feel at ease and in control with his feelings. There's no doubt that he has feelings for you but he is just undecided right now what he truly wants. When individuals make mistakes in their previous relationship, they tend for that mistake not to surface again. That creates fear and uncertainty which causes people to make the same mistake. He is just constantly worried over the outcome of the relationship instead of just going with the flow of things. Mistakes happen in a relationship. There's no getting around that. He just need time to acknowledge his failure, be at peace with it and move on. He seems serious with his feelings for you but its the uncertainty and fear of failure that's holding him back. I just say just let him be. It's also about what you want as well in a relationship. Focus on your own happiness. If you don't like what's going on right now, I say just move on. Nobody needs to deal with that much stress and hassle in a person. He have to decide what he wants and make the changes. I don't think you're over analyzing his situation. You just see it how it looks.

He contacted me again tonight. We were joking around and he suddenly turned serious saying that he knows that he's the problem. He's realized over the last month that he has a habit of "always trying to make himself unhappy" and says that he knows he's lying to himself now. He thinks that now that he's owning up to that, he's able to be happy with someone now. He says that he realizes now that he's his own worst enemy. Apparently he wasn't kidding about his 'spiritual awakening', haha.

I still have reservations, but this totally took me by surprise.

This changes things I think, but I'm not sure how.

Also, I agree about focusing on what makes me happy, I've known this from the start, and I've gotten the same advice from others. However, I'm in a weird situation where I find myself really confident and happy with or without him? I don't mean to sound arrogant or boastful or anything, but I just mean that I'm very stable in myself and I don't base my own happiness on whether or not he and I are together. I would like to be with him IN A HEALTHY RELATIONSHIP if that's an option, I'm just not sure if it is or not...