OP do you wear contacts? because i do and i had very bloodshot eyes a few months back. Was like a ring around my iris i think it is
went to opticians after about 1.5 weeks of bloodshot eyes (gradually getting worse) and discovered i had viral conjunctivitis because the lenses had gotten contaminated which i was unaware of
so maybe if you wear lenses, they could be contaminated like mine were, and it could be viral conjunctivitis. If you do wear lenses, i suggest going to the optician/contacts specialist immediately and getting them to check you over. They will probably know what they're talking about more than the doctor