I think my brain is deteriorating?

It's much harder to do things now. I can't keep doing daily tasks on my own. I have meltdowns whenever I am alone. I am a neurotic, narcissistic worthless pile of junk. I can hardly form coherent sentences anymore. I am always being distracted by something that's not even there. Something is eating away at my brains, and I don't know what. I hallucinate. I lose track of time. I take a nap at 5 PM and wake up at 3 PM the same day. I am eighteen. I don't know what's going on. Can someone help me?