saw a different arm specialist today for my follow up
competent doctor (paraphrased): yeah this deffo looks like cubital tunnel
me: so it isn't. all in my head or a medical mystery like the other doctor said?
competent doctor: (makes eye contact with tech and shrugs) yeah we don't really know what he was on about. we looked at your xrays ourselves and did a new exam. your nerve is definitely real upset. and you're young for this to happen, it's probably genetic combined with your tendency to sleep curled up in a little ball that caused this. mostly genetic bc of the hyperextending elbows
competent doctor: since you're so young you probably will need to have surgery at some point in the next few years. but we can try and delay that needing to happen. do the stuff i said and then come back in 4-6 weeks and if it doesn't feel loads better we'll electrocute your arm and maybe cut it open