12 month old won't eat

I don't know what to do he won't eat anything everything I try he spits out or makes himself gag until he throws up the doctor is taking him off his formula and putting him on cows milk the formula is all he is taking right now how is he suppose to live off of just cows milk I feel like I'm failing him and I don't know what to do I tried to tell his doctor this but his dad said he eats stuff no he doesn't and he wouldn't know bc he's never home he's always working away he was eating cheesies now he won't even eat those idk what to do to get him to eat he won't eat baby food he won't eat toddler food he won't eat speggetios he won't eat my food rarely he will but I can't seem to get him to eat anything on a daily basis and some days all he eats is his milk in his bottle he won't take a sippy cup help please any advice?