Sorry I don't have a solution. But at age 74, addicted to Clonazepam, after having tried a half dozen or so antidepressants over the years, I certainly can relate to this. I simply find I have to write things down in order to remember them.

I'm also flooded constantly with bad memories. When you've lived to be my age and have struggled with mental health issues for as long as I have, you've had more than enough time to collect a whole bunch of bad memories. (Actually, when I try to think up some good memories, I either find I can't think of any, or the occasional good memory I do think up segues directly into another bad memory. It's a vicious circle.)

I don't know how old you are. I suppose what you're experiencing could be the initial stages of some variety of dementia. But my personal, non-professional opinion is that it's more likely to be the effects of medications you may have taken over the years, depression and anxiety along with, perhaps, just a wee bit of the natural effects of becoming just a bit older. Everyone, or at least most people I think, experience some natural decline in memory as the years go by. That doesn't mean they have dementia.