You are better off without her, Eric. She will destroy your self esteem and leave you feeling worthless. You might miss her for a while, but you should keep telling yourself that you are worth better than being treated the way she was treating you. I agree with bedknobs that she only treated you that way because you let her do it, but everybody has their turning point, and this is yours. You should get on with your life without her, but don't think that you have wasted the four years, because your relationship with this woman has been a big learning experience for you. Next time you will be able to recognise someone who has no respect for you, and hopefully you will not be so ready to put up with it. You have the rest of your life to find someone who will treat you better, because all of us deserve to have basic respect. I hope that you find someone who will make you happy and will treat you right, because as you say, it is hard to find a good man.
I hope happiness comes along for you.