Not contacting or responding is a good thing - stick to your guns girl! I know it hurts and you may have a few more sleepless nights but in the long run its what needs to be done. Let this one go for your own good. Sometime down the line you'll find someone who loves you without condition or a bunch of silly excuses to not be with you. I was friends with a different guy since kindergarten and I know he loved me more than I loved him - I didnt want to lose his friendship because he was so important to me and I didnt want to lose him due to a failed intimate relationship - it might not have failed but I was unwilling to try for my own personal reasons. I've lost touch with him now. I miss him a lot but its my own fault.
Your cancer is unwilling for the same reasons most likely. He's not going to change his mind. He's going to keep looking for 'grass is greener' and continue to hurt you. Maybe one day he might grow up - men do that slower than women ya know! But why wait on a 'maybe'?
Live life, find that mind blowing love thats out there waiting on you to be receptive to it. LA is a big town - date, have fun, keep yourself busy and pretty soon you'll be wondering why you thought he was all that anyway! Or why you thought you werent worth being loved by someone worthy of you.
best of luck and love to you