I'm sorry I can totally relate because reading your post was something I would write exactly to the T. Please hang in there. I too have been going up and down w/ really bad downs , am on all kinds of meds and it's like nothing is working...

But I agree w/ posters above. Maybe try and plan your day to the very minimal...
What do your dr.s say? Are they giving your meds more time to work or thinking about switching meds?

I have tried so many med combos it's not even funny. He now has me on parnate which comes with a lot of dietary restrictions, but if it gets me out of this depression it's worth it.
Sometimes it takes a while to get the right med combo. Idk how long because I'm still trying to find mine but even if it's just for your son...hang in there...sometimes I felt that I was useless to my daughter, like you, but after I felt a bit better I was glad I did (still am) hanging on...

Day by day... (((hugs)))