Introduced formula ..

Yesterday I was trying to hand express and literally nothing was coming out and my LO was freaking out so I had to make him a bottle of enfamil neuropro. Well as of today he has had 4 2 oz bottles of formula and I feel like shit .

Has any moms introduced formula but was able to go back ebf ?

My sons almost 5 months and I have no stash .. which is why I needed to use formula ..