You'll eventually have to be nice to the ladies you want to keep in your life, but I agree, you can't be a nice guy all the time. The trick is learning how to make the proper mix. Sometimes too much dickheadedness is a bad thing, but sometimes not. Depends on the chick.

Good luck, and sorry to hear about the problems. You'll rebound. I know its an old cliche, but its very fucking true - There are plenty of fish in the sea.