What is going onnn?!?!?! External Monitor Issues

Ok, everything was working fine until today. I restarted my computer and pram and the problem still persists. The problem is, when i have my external monitor plugged into my mbp and i want to do clam shell mode, i will shut my mbp. I then wake my monitor up by clicking my mouse or pushing enter on my keyboard. Maybe 5 seconds later while im in the middle of putting my password in, the monitor then goes to sleep, as it would if i shut my mbp again. I wake the monitor back up, and 5 seconds later it will shut off again.
Is this a known problem? It only will keep shutting off if my mbp is closed, so im not thinking its my monitor. If my mbp is open, it will stay on. Does anyone have any advise to fix this issue?