Can you become very forgetful when you are dealing with a lot of things by yourself?

Yep... sounds like you should have someone to at least let it all out on. You are pre -occupied, overwhelmed, and just making it through the ordinary day to day routine in life. These burdens on you need to go. I'm older, but know you are way to young to be starting out with all this heaviness on you. You'll be a wreck by the time your 20. But the simple answer is yes.