Sorry to hear about it. That's really tough stuff. I eventually became a coach after going through some tough struggles of my own [0].
In the past I have coached people who felt like what you describe. Usually they fell into one of two categories: 1) Low energy or 2) Stuck with gobs of problems. But I think most were also a mix of both with one being more immediately prominent.
(Strangely, the low-energy ones were often drawn to some energy source as a job or hobby. For example, one of them who came to me wanting to talk about low energy--not my usual thing--was actually an energy expert...for work)
For the low-energy crowd, one opening move I always recommend is tracking and logging. Develop or find a method to track your day and the positive energy flow into your day. Even a scale from 1-10.
Next ask yourself: How can I move this number up by one point?
Pretty soon your next problem will be: How do I keep track of the things that reliably move me up by a point?
For the Stuck with gobs of problems group, it is often vital to continually bring the problems to the surface for examination, usually starting with the day-to-day stuff. You can do this in a journal, in a spreadsheet, whatever you like.
I always recommend that Stuck people also relate the feelings attached to those tasks/situations/projects. Otherwise those feelings tend to relocate themselves to embarrassing situations at work or in other places in life.
People who are Stuck are often interested in BJJ, dungeon crawlers, pretty much any up-close-and-personal hobby with lots of little tricks to deploy.
For that reason: Start developing your set of tricks ASAP. A common one is the development of a proprietary system of organization for all the Stuck Stuff.
> I have so far not found a therapist, friend, or mentor who is of any help.
I'm gonna be straight up with you here and share that this can sometimes be a giant flag to somebody like me. (I won't say red, but it's a flag) I have learned that the flag reads either:
"I need to learn to solve my own problems; mostly I believe in my own problem-solving capacity. I'm sorry but I may also be picking apart your words like a critic/skeptic; can't help it"
Or
"I need to share my own perspectives on why and how everything sucks; after that I will pretty much figure out the rest and mysteriously vanish."
If this is you, you may want to try looking at these outside resources as more of a periodic kickstart or accountability check-in for yourself, as opposed to a lasting therapeutic fix or cure.
Good luck to you.
0. Chronic obesity, chronic depression, chronic severe anxiety, marriage troubles, frequent deaths in the family, member (leadership cadre) of a fundamentalist religion, etc. Overcame all by roughly age 40, but everybody's different...