Insincerity?

Honestly, I feel like this 99.9% of the time when people speak more than an insult about me. I always wonder if they're just blowing smoke up my arse/trying to be nice or sugarcoat something, and there's no sincerity in what they're saying.

This was the worst feeling I often got in class, especially when I got praise from professors I knew to be especially fickle and/or vicious with other students. Part of me wants to believe their words, but a bigger part of me looks at my work and think they're just saying it so I don't feel like rubbish. It's the same with other artistic endeavors, including dance and singing. I've heard people praise me for both in the past, but I don't believe it, at all (and still don't to this day). And the same applies to pretty much everything else, including grooming and physical appearance.

I don't know if it's just me with nearly non-existent self esteem (at least, that's what my therapist thinks is the problem here) or something else, but yeah, I have a really hard time believing in anything others say, especially if it's something half-nice, much less positive.