Mild HFMD with swollen gums that bleeds

My son is 19 months and got Mild HFMD probably from school since they gave a notice of 1 case. First was the high fever. Went to doc, gotten ibuprofen and paracetamol. Then starts the ulcer on the tongue, just one. But it looks painful. Then the rashes on neck which got better after Suubalm lotion. Then now his gums which swells on the right side is spreading to the whole top of his mouth. A little knock to the gums makes him bleed red blood in the mouth. The gums swell like its swallowing his white teeth. I tried applying Soragel but i’m not sure if it helps. I keep giving him plain water to keep hydrated. Avoid hard food like biscuits or snacks. Its been a week. Is it normal? Any advise of remedy?