Why am I always so distracted?

Hi, sometimes I have phases in which I get on well with other people and everyone likes being with me, but there are also phases where I'm totally out of it. That really gets on my nerves because then everyone makes fun of me and I really can't take it anymore because then no one wants to be with me because I'm totally unfunny.

I really don't know what else I can do. It's not about sleep. I've already tried a few things, including melatonin spray and taking a nap.

Please can you help me because I feel like even my girlfriend is losing respect for me because I've been going through this phase for too long.