I am not a medical person but I am just wondering whether your boyfriend fell or was injured before all this started? When I first read your post it seemed to me that he could have a neurological problem or injury. He should see a physician soon to be evaluated.
Good luck to you both.
Itchy, lethargic and hard lump in armpit could point toward a serious cause, but if the lump went away I am not really sure. I hope you find an answer here. Don't want to scare you but, lymphoma has these symptoms. Of course that doesn't mean he has it. Fever and night sweats would also accompany though and the lump in the armpit would persist not go away. You posted in the cancer community is there a specific reason for this? These things could be caused by something that is not serious or is life threatening so your boyfriend should go to the doctor. It might just turn out to be nothing serious.