Sounds like you have a similar problem to me. I have a lot of negative thoughts about myself particularly after a set, even if it goes well. Its just a bunch of sillyness though really! just as tolle points out, these detrimental thoughts are completely pointless. We have no use for them, so why are they so fucking persistent? I dont have the answer to this yet, im reading tolle at the moment and am looking for a way out of this masochistic insanity. I know im a good way there but ive come to realise just how fucked up it all is and just how badly fucked i was before.