Weird arm/nerve sensitivity - lump in forearm

Hello. This has been going on for about a year now. Doesn’t seem to get better (or worse) when training, not training, taking Ibuprofin, not taking Ibuprofin, etc. I have had weakness, numbness and general “odd” feelings in my left forearm. No pain. Was convinced I had ulnar nerve entrapment / cubital tunnel syndrome. But I’ve also been experiencing weird “shocks” at times when I move, and have sensitivity (think very ticklish) on the underside of my forearm. I stumbled across this link (https://www.researchgate.net/figure/Bulky-mass-over-the-middle-ulnar-side-of-the-distal-right-forearm-arrows_fig2_301664478), and not only do I have a weird lump almost identical to that when flexing my arm, my symptoms are almost verbatim what are described there. I’ve never heard of this before, and it seems to be pretty rare. Don’t even know what this condition is called–just have the caption from the picture. This is probably way outside your wheelhouse and something I should see a doctor for…but I can’t find anything else about this condition or what I can do to treat/manage it (e.g., ice or heat, stretches, PT, etc.). Wondering if you have any ideas, or if I should just go to the doctor. Thanks

This would probably need in-person evaluation and, if nerve compression is suspected, potential further neurological testing. Unfortunately not much I can do from here, sorry.