Tired of the Relationship Tango

Hi there,
I have been reading a lot of books about co-dependency this year and I am making some great progress. Right now I feel I am sort of in the chaos of it all since a lot of emotions and truths are coming out.

One thing that still puzzles me though...
Last year me and my roommate went away together and we slept together. We had been attracted to each other for ages, but he had a boyfriend and I was still having feelings for someone back home (we are in Europe). I think my roommate has tonnes of potential for life but he hasn't been really 'making a go' of being in this foreign country. For the first year, he pretty much stayed in for most of the week in his room. He told me he suffers from depressions at times.

So when he said he had strong feelings for me I panicked and said I thought it wasn't a good idea. I wrote him a long note telling him that I needed someone who had more going on in his life. I just felt like I would be swallowed whole.

We still do pretty much everything together and I love being with him, but I just couldn't say yes and fall into it. The bad thing that I did is that we continued to sleep together off and on and I would be ready to try it and then I would get that panicky feeling again.

Well, months passed and I finally decided to see a counselor at which point he brought up co-dependency. Soon after, I thought that saying 'yes' doesn't mean a life commitment or anything and we definitely have something. Of course, when I finally said 'yes', my roommate told me he doesn't trust me anymore and needs to build up the trust again.

Well, it's been 6 months now...I have shown a lot of affection, caring and I pretty much think of him as my boyfriend anyway. He still isn't ready and says he can't promise anything. A bad thing is happening too...the more I reach out and get no love in return the worse I feel about myself, the more unlovable I feel...I don't feel needed at all and it is making me more jealous, suspicious etc.

I am about ready to move on but it would be a real shame if we didn't try it out. One thing I know now is to get my life back on track and stop focusing my energies on him...in a nutshell, getting a life.

This goes back to my question and keeps nagging at me. If a co-dependant person looks for people to 'fix', people to live through, why would I have said no to him in the first place? I just don't understand that on one hand when someone is chasing me I run the other way and when they give up I feel like garbage and try and get them back...can anyone explain this dynamic?