I fully agree with myfavouritethings - this is about your self esteem, and it sounds like it's a pattern you fall into over and over:
Surprisingly in general life I'm pretty normal /independent. Then it comes to men /dating and I'm a pathetic too attached idiot
I agree that calling yourself "pathetic" and "idiot" isn't necessary (or kind - be a bit nicer to yourself!) - but it seems there is something about romantic relationships that makes you think either you don't deserve to be treated well, or that you can "fix" a man with problems and then be rewarded with a happy relationship.
That last one is a particularly insidious and widespread problem - women and men are encouraged to think that "the love of a good woman" is what redeems men from their previous bad ways. This is bad for women because it encourages them to stay in relationships which are bad for them, makes them feel like a failure if the man doesn't change ("but surely if he really loved me he'd want to do xyz! Therefore I must not be loveable or worth changing for") and puts all the burden of controlling a man's behaviour on to the woman, not onto him. Women are encouraged to think "but if I just hang in there, finally I'll get the perfect man because I deserve a reward for all my hard work". This leads to "I gave you the best years of my life and got nothing in return" syndrome - the woman is bitter that she wasted her youth running after some drunken, selfish arse hole with the unspoken expectation that this would mean he owed it to her to change into the perfect man at some point. When he doesn't, she feels cheated.
It's also bad for men because it encourages them to abdicate responsibility for their own life and health, sets up their romantic partner as their parent rather than equal and makes them passive when it comes to making decisions ("I'll wait until the perfect woman comes along, then I'll magically get my shit together for her. Meanwhile, I'll drift through my thirties, developing a drink problem and never really thinking about what I want my life to be like in ten years. Fictitious perfect woman will be along soon, I expect she'll tell me what to do ")