One week old baby formula feed

I have a one week old baby and have been EBF him since the hospital. Recently though, he has not been getting enough breast milk due to refusing to latch. I broke down and gave him 2 oz. of Enfamil Formula and cried and cried and cried :( I know fed is best but I feel like a failure! Any other moms have to give up breast feeding so their babies could eat? How did you do it? I guess breast feeding just isnt for me. It was extremely painful and exhausting 😣😣😣😣