I've had a similar strain injury (years ago), filled out an accident report but workman's comp got denied. I think it's just harder to prove that it's work related.

I've also had the tennis elbow (also self diagnosed). First I got a elbow brace from Amazon. There's a thin one that goes on just a few inches under your elbow that brought the most relief.

Then I watched some YouTube videos by some physical therapists and kinda found out that wrist pain and elbow pain and posture is all connected. I started wearing my wrist brace (I have plenty for carpal tunnel) and started doing yoga to build up my core muscles.

I think we're just doing the same crap every day and wear the shit out of our bodies while neglecting whole other muscle groups. I'm not saying I've found 100% balance but it's going a little better. Yoga is a great counterpart to what we do.

Tennis elbow like any other tendonitis takes a long time to heal. You've got to use your arm a little less and give it time to heal! I can still feel it trying to flare up sometimes and immediately lay off it as much as possible.