Painful Lump Under Jaw - Seeking Advice

I been to my Gp lots of times with lumps / lymph glands /nodes whatever the right term of word is, not sure if your lump is referred to those conditions. I’ve never noticed mine until I had glandular fever in 2020 I believe that’s what may had triggered them or the covid vaccine. I’ve had constant problems with these lumps it’s progressed from under my jaw to my joints. It wasn’t until recently I’ve been told it could be a cyst then I was told the lumps aren’t lymph glands because there also on the joints but are a swelling of the muscle🙄 They had sent me for a scan but nothing concerning was found. I was just told that I did have “a lot of tiny glands all over my neck” but there’s no growth or anything worrying. I haven’t been put on any medication for this yet either when these lumps arise they are painful. The only sort of advice I’ve been given was understanding the sizes and touch for changes that’s when to go back and see them I’ve had experiences with the lump goes down but never fully goes away it’s always there. Lately I’ve also been experiencing palpitations on them and I haven’t even made the gp aware of that yet I’m also new to the app😂