How deluded can a mind get before it evolves into a fictitious phase of make-believe?

I can't understand my brain. Logically I know most of what it thinks about myself is inaccurate however I linger on the abuse it constantly hurls around my head in the direction of any possible fault i possess. Even the ones I apparently don't possess. I'm not far gone enough to fall prey to it completely. I'm wise enough to understand that most of what I think is ridiculously untrue, yet my thoughts are strong enough to cause me emotional chaos. To hate every inch of my being. My head is prone to passiveness and therefore the only distinct indication of my being far from pathetic, stupid, worthless and unattractive is the fury in other people. I'm not eating this evening. I'm so caught up in my anger for being so flabby and gross that creating a salad and being near food in the kitchen brought about nausea, rather than salivating-factorage. I know my stomach's hungry but the abuse in my head is enough to turn me away from food tonight.

Pretty sure I'm my own fucking worst enemy. And I can't do anything about it. I'm not strong enough to stand up to it. I doubt I ever will be. I hate that when I get like this my head doesn't allow for positive thinking. All I can picture are the criticisms anybody has ever thrown at me. I'm a tragedy because I truly feel I can't do anything right.