8 month old won’t sleep

My 8 month old will not sleep through the night. He is up almost every two hours still. It’s very exhausting and frustrating to say the least. What do you recommend i do? I asked his doctor and they said it was just a phase he’s going through and he’ll get through it. I know he’s teething but the last time he slept through the night he was about 3 months old. I have given him pain medicine to see if that would help. He’s breastfed so I’ve tried supplementing with formula at night but it’s always a fight to get him to take a bottle. If I’m lucky I’ll get between 2-4 oz in him on a good night. Most of the time it’s just 2 he will drink. I’ve tried earlier and later bed times. I bought a weighted sleep sack from nestedbean and it hasn’t seemed to help much. I’ve tried feeding him more during the day too. Since i have to breast feed him to get him back to sleep in the night or he just screams and won’t stop. Please help.