I understand everything you have said and feel much the same

I've been on several different meds too and still trying to find the mix that helps. My current one while it helped for a while seems to have stopped now. I am struggling with similar lows and the same apathy towards everything. It's hard to see a point when things are this bad I guess.
But it won't always be like this. Thats what we have to tell ourselves otherwise it is just too overwhelming. Things can and will get better, it just takes time. And meds take time to help fully, sometimes up to 6 weeks I think so give the cymbalta a chance.
But keep a close eye on the side effects, I know some people where it has made them pretty suicidal. I'm not saying this will happen to you, but I just wanted to make you aware. I took it for a while and didn't have that problem.
I hope things begin to pick up for you soon