Only napping with a bottle :(

My lo is 4 1/2 months. Lately he has been super fussy and just overall a pain in the butt. He gets so whiny easily now which is unusually because he is a very happy, healthy baby. Lately he has been refusing naps but is so tired his eyes are red and he is practically delirious from being so tired. The only way I can get him to sleep is if he gets 1-2oz of formula. Even if he just ate an hour ago:/ I am at my wits end. I don't know how else I can get him down without CIO and I don't want the bottle to become an issue.

Any advice?