I have that problem too. Out of the blue I will just have these awful thoughts about everything around me, and I'll try to think to myself "why, theres nothing wrong with anything but me." But that just makes it even worse, because then not only do I obsess over how negative everything is, but I obsess over how much worse I make everything.
I hope seeing your therapist helped a lot, and if you ever want to vent, feel free, we're all ears.