I really like this girl but she has a boyfriend. We kissed. What do I do?

She has to make the next move because she's the one with the boyfriend!
It's OK to tell her you like her a lot but will wait while she decides (it could hurt you, if she just likes two guys fighting over her).

what should i do though, i dont know what to do...

Not that I recommend these but you can
1. ask her to be your girlfriend and break up with the other guy
2. ask her to cheat with you and date you also
3. ignore the fact she has a boyfriend and keep coming on to her

Or of course you can do nothing and look for another girl, since this one was taken. And hope this boyfriend does not hear about the kiss and want to punch you in the mouth

the thing is, i dont want her to cheat on her boyfriend, and she does still sort of like him, but the thing is i can't let her go, i actually feel she is so perfect, and she is the only person that understands me, so, should i tell her how i feel and see what she does, she knows i like her, but she tells me not o, because she feels bad cause she has a boyfriend..

Can't have it both ways bro.

In my opinion you're better off finding another girl. Relationships that begin with cheating usually end that way, too.

You have crossed the lines of good behavior because you have spent far to much time and attention on her, and now you have a mess. She doesn't know what to do, so tell her this isn't right or healthy, and leave her alone and you both do other things, but NOT with each other.

Yeah it sucks and will hurt for a while, but at least you have a chance to think of the right thing that should be done, without each others influence. That has to be better than keep going down the unhealthy confusing path you are on now.

I mean even if she dumps her boyfriend, you already know what she is capable of doing behind a boyfriends back don't you? How old are you both, and where the heck is this boyfriend that she can spend so much time with YOU in the first place?