This is hard to follow, even reading between the lines. People can't see inside your head to understand the context behind these thoughts. Communication like this will scare off future employers and social contacts. More the incoherency than the tone of being depressed or negative (which also aren't great, but this is worse). Caffeine does not cause this.

If you don't address this your situation will not improve. You must acknowledge something is not right with your mental state and focus on getting the help you need. Please speak with a social worker if you feel you've gotten insufficient medical care to this point.

I wish you well.