i dont really have an answer for you, i was just wondering if you could tell me specifically what you mean by biting.. were you chewing off skin or biting the lip as a whole? because im 18 and i have been chewing skin off my lips due to anxiety since i can remember and it has never caused a blister, just a thin scabbing.
well after thinking back i remember i would bite the top layer of my bottom right lip, then i would adgitate it by rubbing it untill it would hurt. I know pretty silly thing to do but kids will be kids. Im not positive if its a blood blister beneath the skin or a broken blood vessal. Anyway ive noticed another one has appeared on the left bottom as well as some pin sized ones and its kinda weard because i havent bit my lip for at least 25 years. It never really botherd me as it was very faded but every now and then its really noticable. Sorry youve had anxiety for what ever reasons but think possitive and good things will happen.