Help!! Need some formula advice

My son is 6 weeks old and allergenic to dairy. I went dairy free about 3 weeks ago and his symptoms clearned up. I am losing my milk supply and have tried multiple different kinds of dairy and dairy free formula for supplementing while I get my supply back up again. As of right now I'm using silimac alimentum formula well ..... he has been crying none stood since yesterday. Super super gassy. Green slimey poop. Just so uncomfortable. He eont sleep very long and wakes up crying. I am at a loss of what to do. I have to get him on something so when he goes to daycare he has food. Is their an adjustment period for him to get use to formula maybe or should I stop with this kind and attempt yet another. I'm scared to keep giving him formula due to it hurting his stomach but I cant pump enough out to store let alone feed him strictly my milk. Any words if advice would be welcomed!!!