baby's upset tummy has us both in tears!

my lo is 8weeks and his little tummy is always so sore after he eats! he's only had my milk, but drinks it in bottles maybe once a day. he's been fussy for about a month, but it's gotten worse the past few days. he's pulling his legs up and grunting, and crying until he can fall asleep. good belly is hard and you can tell he's in pain. he sleeps for 3-4 hours at a time. he poops watery yellow every day and has enough wet diapers.

he also spits up a lot, sometimes forcefully. he's puked a few times too.

we've tried gas drops, gripe water, the windi (essentially sticking a qtip up his butt a little to stimulate farts and poops). we keep him upright after feeding, burp (if he can). nothing seems to help!

what can I do? is it something in my diet? is this something he'll grow out of eventually? or is this something more serious? I hate seeing him in pain 😢😢