Why do i screw everything up?

I'm okay with small things like watching my son, and getting groceries but when it comes to things that matter, its inevitable that something is going to go wrong. Like I forget something really important or I drop something super important and it breaks. I'm tired of living life this way, cause I try really really hard to make it better but it never works. Like I make a mental list of everything I need, or need to do and then the most important things will just not be included. Nothing I do seems to matter cause I'm destined to idiocy. I even tried making real notes with pen and paper but that never sticks, I forget to make them. Its effecting my life and people around me, and I'm depressed and afraid of losing everything. What do I do?