I feel really bad that i blew it with someone i care about.?

Meet this girl in work a few weeks back,we get on great and really get on and chat whether that be texing,talking in work or over facebook. also we flirt all the time.We are both very open with each other and have chatted about lots of stuff including .So i ask her out for a drink tuesday just gone.She said yes but its not a date and i agree to it.So we go out have a a good time,chat over a few drinks.We talk about how many people we have been with in the past and that even know she has been with way more then me i dident care cos i like her and we have all had our fun even me.So i was driving her home that night and we got caught in the moment and started to kiss and take each others clothes off and she stoped and said i cant do this i said ok..i dident mean to make you feel like this.she said your just like all the other guys,we talked a little and sais i was not after that i just really like her and just got lost in the moment with her.We talked a little more and i said i was intrested in her for her and not and if you change your mind just let me know.She told me she had some stuff to sort out with herself cos she is in love with someone she should not be.Then we hugged for a while then started to kiss again,after i dropped her home and she sent me a tex saying how lovley i am and really fun it is hanging with you.Well things have changed a little since then,she does not come over to talk to me as much as she used to or even on facebook,We still get on and talk but not in the way it was,I asked if she was free to hang out next week and she went mad saying why so that can happen again.She then said i had that all planed what happened when we went out and i thought of it as a date and i just took advnage like all the other guys.I said sorry but i do like you,i just caught in the moment,i have respect for you,i dont know how many times i can say sorry for what happened and if you want to be friends then thats ok with me.She then said if thats what you say...i just dont know how to make things right..i feel really bad