Caffeine affecting babys sleep

My son is 4 months old. He is breast and formula fed. Only breast at night. For the last week he hasn't slept AT ALL. He was sleeping so good at night. I know it could be sleep regression. But I also thought it could be caffeine. I drink A LOT of soda. Has anyone had this problem & had to cut caffeine out of their diet? (Im 100% fine with it coming to that, starting today I'm trying no caffeine at all to see if it help. just want advice)