Dear Infinite, I'm so sorry that you're having to deal with this. I can feel your sadness in your words.
Having said that, I have only practical advice for you. Do you have a primary care doctor? If so, it might be time for a checkup to see if there's some non-psychiatric illness that's causing problems. Any prescription meds, OTC meds, and supplements should be evaluated to see if they could be causing problems.
Next is to get your psych meds prescriber to take a look at your psych meds.
Someone else mentioned lists and tips like that to help. (If I do that, I still need to put a big sign on the wall that says "Check your lists, check your calendar" in a place where I can't miss seeing it.)
I have some problems like the ones you mentioned but maybe not as bad. Or maybe I have just had the option to cut back my list of responsibilities more. I did just get a letter in the mail yesterday telling me that I forgot to send in some very important paperwork and am going to suffer undesirable consequences because of it.
I haven't figured out what's causing my problems, although there's one med I take that I'd like to stop taking but haven't yet because it will involve months of tapering.
Therapy helps me, too. It seems to free up mental and emotional energy for me.
Then there's diet, exercise, supplements, acupuncture, meditation...well, you know how it is when you have a chronic illness. The list is endless.
If you've already done all the above, hugs to you. Hugs anyway. I have some days when my brain is totally, normally clear and it feels so good, but there aren't many of them.