@christiemarie86,
What did you do wrong? I tell you: in all three cases you let the guys treat you like a doormat. You ran after them and you made yourself available, not only that you let them mistreat you.
First thing you should do - get some self worth! There is no need to run after boys and do everything they want you to do in order to be liked. Actually, that's the kiss of death for sure. No one wants a doormat!
Since you have a pattern of always getting into the same situation where you pursue a relationship and make yourself available to a point of annoyance,
I'd suggest you seek some counseling to break the pattern and learn some techniques to increase your self worth and gain confidence.
You need to work on yourself first before you get someone else into the
equation. Believe me, you'll be a better person for it and you won't take crap from anyone - and you shouldn't!
Good luck!