Self-sabotage seems to be my fortea (sorry for spelling). I get in a good relationship or job and feel like its going too good and find ways to make it not work. I think this has to do with the fact that feeling good is uncomfortable for me. Not my usual, so I go back to what is usual. I am really trying to fight that. I have also given my check card to my bf and we discuss what I'm going to buy before he gives it to me and then I give it right back. B/c I know I'll overspend, normally not meaning to.
I agree with Moanie. You need to try and look at the positives. I know that can be very tough. Its something I struggle with. I have found that (for me) if someone keeps telling me I'm good at something or that I'm loving, they are probably right. So I have started repeating those things to myself when the negative thoughts come in. I may not believe them at first, but hopefully with time I will start to believe them.
Keep posting. Sending you gentle hugs.