Head scan...

I feel for ya man. I went though years of tests trying to figure out my chronic pain, weakness, and sore/still muscles and joints. Had every test you could think of.
Was treated for a while for rheumatoid arthritis, tried all the popular drugs, nothing made me feel better.
Then changed docs cause my was moving. New doc thought it was something else completely. Tried a bunch of other drugs, nothing helped.
Gave up for a few years and just lived with it.
Then started seeing a new guy, ran a bunch of tests and says I have adrenal fatigue. They also found out my testosterone level was 11. Doc said it was the lowest he'd ever seen, said that was like nursing home level.
We tried the creams, with no luck, and then went to the shots. Now my level is like 850.
When I first started on the shots I could tell right away, it was like I got my life back. I had energy to do things, but now after a couple years, it seems they aren't helping as much, but I'm sure its still helping.
But, I still have chronic pain in the muscles, joints, and frequent feeling of just being too tired to do anything, or feeling too weak to do anything.

Sometimes I think these doctors are just playing a quessing game and they don't really know whats wrong with you. And they don't want to take the time to figure it out. They just throw drugs at you till something helps with the symptoms.

One thing you have to watch out for with the T-shots. At some point you body might start converting testosterone, to estrogen. That's where I'm at now. T is high, but so is the estrogen. Taking pills for it, it's not coming down. Big surprise. If we don't figure out how to get the estrogen down soon I might start growing man boobs or something. lol

Good luck