Teething disrupting sleep for 6+ weeks

I’m going to check in with a pediatric dentist when we get back home in a few days but. We were traveling out of the country for 3 months and these last few weeks my little one is working on at least 4 molars. If I don’t give him Tylenol before bedtime and around 2-3 am he keeps waking up screaming or crying every 90 minutes or so but I’m worried because I’ve been giving it to him for 6 weeks.

Is this normal?

He does not let me brush his teeth and insists on trying to do it himself so I’m also worried about cavities. He doesn’t eat any sugar.