can't move on

My husband and I kind of separated last Xmas but we're still living together in the same house. He found out he had cancer in February so I said I'd stay with him until he got better (his cancer is one of the more easily curable). I was hoping this would bring us together but he never wants to talk. Or if we do, he just starts to rant about everything that he thinks is wrong about me. Being stuck like this I can't move on but at the same time I use it as a crutch because I'm scared of what's out there.I don't know that I can find a good man, so far I did a great job at picking the wrong ones. This is my 3rd marriage and each husband, although they started being nice,  after 2 or 3 years started to manipulate and control me in some way. I tried to make it work with the first 2 for years before giving up and leaving to keep my sanity. This last marriage I don't want to stay because the older I get the less likely I could find someone nice who will treat me with respect and courtesy. But at the same time I feel like damaged goods and that no one will ever want me thinking there must be something really wrong with me to be married and divorced 3 times.