Mate, nice guys don't go to jail. Nice guys don't do stuff which will put them in jail.
That being said, most guys are nice....that's really just the basic of what a guy needs in life. but as well as being nice, a guy also needs to have qualities which makes him stand out above all the other nice guys. If being 'nice' is all a guy has going for him, then he probably will end up at the bottom.
I have to say though, you're crazy if you think a guy should always respect women. A woman shouldn't be respected just because she's a woman - she should be respected only if she behaves in a manner which is respectable.
As for this girl, you're simply too young for her. Find a nice girl who's 10 years younger than her.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.