Messed up milk supply

My son is currently 18 days old. I've had a great milk supply since I gave birth but 5 days ago he had completely drained me on both sides and was still crying because he was hungry so I Gane him sind formula I had on hand. Then the next day I was out in the store and he started crying out so I gave him formula again. Because he eats from a bottle so much quicker I also started feeding it to him at night so I could go back to sleep quicker. Now I want to get back to exclusively breastfeeding but my milk supply is no where near enough. I'm constantly left over with a hungry son and I'll have to give him a bottle just so he'll get enough to eat.

I wish I never gave him formula in the first place. I miss the bond from breastfeeding.