Should i go to a Psych hospital?

Lately I have been having nightmares of me killing the ones I love, this happens during the day as well. Sometimes I think I might act on it. Also I've been thinking of committing suicide. This has been going on for weeks, I actually have a plan, I was going to save up my Lithium and take it when nobody is home. I always feel like killing myself, and I don't know if I should go back?