4 month old sleep issues

K ✨
Hi ladies, 
I desperately need help!! 
My 4 month old is waking every 2 hours at night as of the last 5 nights and the only way he will fall back to sleep is with a bottle!! 😭 
Background info;
-He is formula fed every 3-4 hours during the day approx 120-180ml depending how much he will take. 
-He has 3-4 naps during the day but won't sleep past 40 minutes. He can't self settle.
-The only way he will sleep is if I pat him to sleep, he sleeps on his tummy. (Will not sleep any other way).
-He is a big boy, born 10.9lb and is now 18lb. 72cm long so also very tall. 
-He also has solids at breakfast (rice cereal) about 6 teaspoons. 
- He could also possibly be teething as he tries to shove everything in his mouth and gets frustrated easy.
My husband wants to try CIO but I spoke to our paediatrician who told us he is too young for this method dan to wait until he is six months old.
Does anyone have any advice ?? Or have you been through this? If you have a schedule to offer that would be great. I'm willing to try anything! It's our first baby and we know it's our fault he can't self settle as we have cuddled him to sleep pretty much up until he was 2 months old.