Am I starting to go insane?

I believe I am depressed, although i have not had any diagnosis or seen any psychiatrists or counselors or anything. I have come very close to suicide over the past few months, even to the point of holding a gun to my head. But for the past few weeks I have been completely unable to enjoy anything, all I want to do is lay around and sleep. When I hang out with my friends all I can think about the whole time is how much I hate myself. I have been really preoccupied with my own suicide. So far I have been able to refrain from it. But about two weeks ago I started noticing things just didn't seem right. People will tell me things that happened that I don't remember or tell me something happened one way and I remember it happening completely differently. I also feel like I cant control myself, kind of like I'm in a dream. I'm starting to doubt everything.