Yea i've been a dick towards one of my first ex's about 6/7 years ago now.
The most recent girl was a bit murky. She told me she loved me then did a complete u-turn. I was playing her cool as well and put in a lot of effort towards getting her interested and feeling happy. I do love that girl. I did rant at her when she rejected me but it was justified. I think it was about 3 rants in a month (think how hard it is being told by a girl that she loves you and wants to spend her life with you, then inviting her to your house only for her to do a complete u-turn on the second night and then having to put up with her for a month whilst she stays in your house and ignores you), then I kicked her out of my house and then no contact in a month now (she has me on fb and has my mobile number and my last message was telling her that I am happy to remain friends seeing as we aren't going to meet up again).
But you know, we all have this ****. My only worry is whether I behave with dignity with a breakup now because at the end of the day you just realise that there are plenty more people out there and you really don't want to carry such negative patterns into new relationships. You also have to stand up for what you believe in but you have to know what you believe in first... Sounds like you might not be entirely sure what you want from life atm. Breakups, in any form, really do wound people though. The trick is to realize that you can get the same thing from other people and often it is 1000x better.