How to get 4 month old to sleep at night

Em

So my sons usually down for bed at 10:30 but since he’s started teething at 3 months he’s been off schedule for almost two months and I feel like his bed time gets later and later. He feel asleep at 12:30 am week ago and then 1:30 am this week. I feel like I can’t get a break because he doesn’t like naps anymore and if he naps it’s only for 20 minutes 45 minutes on a good day if I’m lucky