Oh please honey don't get down on yourself because you didn't manage the 'proper' response when some jerk acts out his messedupedness.
The only thing over which I'll agree with you on this is that you are definitely picking the wrong men over whom to dote your kindness.
You should not ever have to change being a caring, loving, kind person just because the world is spinning towards bitterness and cynicism. Yours are the qualities that endure for eternity, it is what has made good mothers, wives, and caretakers for thousands of years. The fact that we have a nation of misfits and dysfunctional attitudes does not negate what is good.
Yes, yours is a healthy attitude my dear, but it just doesn't go far enough. You need to value and appreciate these qualities in yourself first, understand that you are a valuable person and that the treasures you hold in your heart are to be guarded carefully before you share them with others. This is what you really need to work on, self-esteem, not to change who you are, but who you allow to get up close and personal. This is what constitutes a truly healthy person.
There are definitely nice men out there. Oh, I don't think they are plentiful in a culture that consistently undermines what is to be be a 'real' man or woman, but if you look and wait patiently you will find them.
Make good friendships before you get initimately involved. Find your passion and pursue it, and when you do, get to know the people who share your passion and develop friendships with men and women, who are like minded. Take it slow and easy, and if someone wants to rush you into something, then don't bite. Nothing that is initially rushed through ever really works, whether you are baking a cake or building a relationship. Too many important steps will be missed and the results will be disastrous.
You've been given lots of good advice. Now take it in and weigh it against what you know that you know inside is right. Put what is wise and good to use and discard what just doesn't click, and then go on to live your life like the wonderful, victorious woman you have every right to be.