I don't know if this is related to bpd, but in the rare occasion that something good happens or I feel happy, I try to suppress it because I feel like I'm "kidding myself" or that I don't deserve it.

If something happens that's positive or I hear positive news, I don't get my hopes up because I assume it's some kind of trap, or that the good thing won't actually end up happening.
That or I expect my life to go downhill again right afterwards. Anyone else feel this way?