Is it worth re-establishing

My son is 5 1/2 months and I’m not ready to give up breastfeeding. His 1st month was amazing! The lactation consultants at the hospital were amazed how well he latched. I never had nipple soreness or anything and every time he nursed he took in a lot and was gaining more then he even needed to. After a month he stopped gaining weight completely so I had to use formula along with nursing and pumping but that turned into me being lazy and just making him formula during the day. I still nurse him during the night. My plan was to exclusively breastfeed him for at least a year but hoping for 2. I’ve been really down about it the last few days and makes me cry thinking about it (like right now). I also feel very alone in this process which doesn’t help. Today I decided I am going to pump every 2 hours everyday and power pump once a day. Is it pointless to start re establishing at this point? Will even work?

For reference the other day I pumped only 4oz while power pumping, 15 hours after nursing him.