Wendy,
I am sorry to hear that you have been hurt (again).
As for trying to change, please don't. As they say "a leopard can't change his spots". Neither should they try. Remember that when all is said and done, you have to look yourself in the mirror every day, so you need to act the way that you feel right about acting, not how you think will get you what you want.
(slight subject shift)
Often over the years I have seen women get treated like crap by men, and I never can understand it. Many women claim to ant a "nice guy" but I can't count the number of times I have seen a woman keep going back to a jerk that treats them like crap. Why? Lots of reasons I have gleened from years of observation and from serious talks with various female friends.
Suffice to say that there have been many times where I have thought of changing my behaviors to be more like the "bad boys" that seem to do so well. Unfortunately, or maybe fortunately, it is not in my nature, so I remain the "nice guy" that I am.
Do I get taken advantage of? To some extent, the answer is yes. At group events I do triple (at least) my share of the work so that things run smoothly. That allows some others to slack. Still most people have a good time, and I can hold my head up when I see the man in the mirror. I can look him in the eye.
So now, for all you ladies out there that are tired of getting treated like crap, rebel! Don't take it. Look around for some of those nice guys that are out there. They may not be as flashy as the bad boys, but in the long run you will be happier.
Sorry for turning this into a rant, but it pains me to see such a nice lady getting hurt (again) when I know that there are nice guys out there that would treat her (you) right, and worship you for who you are.
Please don't let those few bad apples spoil everything for the rest, and please don't let it harden you to the point where you can't trust anyone and you can't enjoy life.
Please accept this sincere cyber-hug with the reassuring words that it will get better.
Wristshot