I don't believe you have bipolar disorder. Nothing makes me think you might.

I do think you have a coffee addiction, as you said you might have. Both migraines and an unusual sleep cycle could very well be a result of that. Not sleeping can cause problems that could be described as manic, but it doesn't really sound like mania either.

I also think you have some anxiety issues. Derealisation is common (the feeling of unreality). Thinking you have a serious illness and imagining doing bad things are very likely part of it. Both are also very common.

The question is whether caffeine causes or has caused your anxiety problems or that it's unrelated.

It's (as far as I can tell) very unlikely it is BP I wanna stress. It's completely in line with anxiety issues and drinking too much coffee.