Random swelling under lip what could thus be? nd am i in danger+

Probably truma: I would speculate tht you are somehow biting your lip at night or when you are unaware and that the swelling is from this trauma. If you have fever and redness it could be a cellutitis and you would need treatment with an antibiotic. The doctor who is treating you with your medications might be best able to assess this. A dental condition could also be a cause.