It’s human nature to want to blame someone else for your mistakes. What you need to admit to yourself is that the reason your relationship failed is most likely because you failed, rather than the other way around. You missed the little cues that her interest level in you was dropping faster than an 18-year old's prom dress, so that when she finally told you “I think we should see other people,” or more likely, she starts seeing other people behind your back, you were shocked, hurt and ended up blaming her for the failure of your relationship. Women aren’t completely innocent when a relationship has failed. In fact, they could be much more direct with how they feel, rather than rely on subtle cues that things aren’t going well. Unfortunately they’re not, and the sooner you learn this fact, the better.