Thank you so much for replying, Jennifer!
I do sometimes get depressed, but I think this goes even deeper than that - I feel it's in my very being to see myself as worthless.. There never was a time I thought I was OK - in fact, I've thought it would have been better for my parents had I never existed. It's so hard to turn these thoughts around when the two people who were supposed to love me more than anyone in the world didn't.. I now know it was about them and not me, but it's still so hard to start thinking that I'm actually a good person and deserve all the good things in life just like anyone else..
Just gotta keep working on it..