Why is is so hard to be loved....?

My greatest downfall when it comes to my illness is the fact that I can not hold down a 'normal' relationship.
Throughout my life I have gone from one guy to the next without fully recognising the extremity of the amount of men I had have walk in and out of my life.
I recently decided to look deeper into it and draw up a list of all my partners over the last 10 years, then analyse them statistically like this....

30 Men   (either partner/boyfriend/or significant in my life)

24 -  Had sex with
16 -  Obsessed over
14 -   I 'fell in love with'
11 -  Abandoned me
2-     Relationships lasted longer than 3 months
12 -  I've met in a club/bar

I looked at this list and could not believe it was that extreme. I knew I wasn't a slut or anything, because I could remember each and every guy, because they all meant something to me or were a significant part of my life at some point if only for a couple of weeks or months.

But what hurts the most is that all I've ever wanted seems so simple to me... I just want to be loved by someone that isn't going to walk out and leave me. I don't care about money or success or anything material when it comes to finding the man I want to spend the rest of my life with and so each time I met a guy it always seems so do-able, it just never works out how I expected it to and I still don't know why.