I’m a failure 😔

When my baby was born he weighed 6 pounds 5 ounces. I’ve been almost exclusively breast feeding but supplementing formula here and there. When he nurses he’ll nurse for at least 30 minutes at a time, sometimes he’ll nurse for over an hour then he’ll normally fall asleep. He’s had at least 5 or 6 wet diapers and 1 or 2 poopy diapers a day so I thought he was getting enough but today at his one month appointment his weight went down to 4 pounds 15 ounces. I feel so awful, I feel like I’ve been starving my baby unintentionally. I’ve been feeding him on demand and letting him sleep as long as he wants thinking he would let me know when he was hungry. I just feel like a horrible mother. I’m still going to breastfeed him but I have to give him a bottle of formula after nursing him to make sure he’s getting enough. Breast feeding has been hard but I want to succeed with it so bad but at the same time I’m thinking what’s the point considering it isn’t enough and I have to formula feed him any ways. I’m just really disappointed about it 😢

UPDATE

My little man is doing great he’s up to almost nine pounds as of a few weeks ago, I’ve still been breastfeeding and giving him 4oz of formula, he even has a little double chin now 😊