It is very normal for a baby's sleeping pattern to change. Especially at the 3 month mark. They go through a growth spurt and require more milk in order to do the growing! Night feeds are actually the best for your supply, and bub usually knows this and can have his best feeds then. They also become more aware of whats going on around them, and can be distracted with day feeds and rely on night feeds to get what they need.

Formula making them sleep is an urban myth! LOL. Some people might claim that it worked, but IMO it would be a coincidence that bub was ready to change sleeping patterns anyway. Others will tell you that it makes them worse because it's rougher on their little tums and they can get upset by it.

Neither of my babies have been sleepers, so I can sympathise! Usually these rough patches pass tho or you can all slip into a new routine. Best thing is not to worry about it, and just go with the flow, and know that it's completely normal for babies to NOT sleep through. You're a lucky one that got to experience it for a while! hehe.

I'll send some sleepy vibes your way