Colic at 8 weeks?

I mentioned this in another post but I'm wondering what you other momma's think...

So my LO will be 9 weeks tomorrow. Some back story first. At around 4.5 weeks we found out my son has a cow's milk protein intolerance. He was a very fussy baby during this time. We put him on hydrolyzed formula and after being on that for two weeks he was a completely different baby. He took good naps in the day and went to bed at 9p sleeping until 1a pretty consistently. He had a few nights where he would wake up in between feedings for a diaper change, but for the most part did really well not waking up again until 430-6a.

Fast forward to 7w 5d and my LO became a lot more fussy throughout the day and had trouble sleeping at night. Unfortunately for me it was the same day my SO went back to work, night shift. My LO will be 9 weeks tomorrow and for over a week now he won't sleep consistently... At night or take naps during the day. He wants to be held all the time. As soon as I set him down for bedtime or nap he wakes up crying within 20 min.

I've been thinking this entire time and I'm still not convinced otherwise that it's a sleep regression / mental leap. Another point I do want to make is that he does have more gas than he initially had on the formula and he's lost his appetite. He was eating 3oz every 3 hrs but now he doesn't want 3oz, sometimes he'll only drink 1.5/2.

If you've made it this far, thank you. So today at his 2 month I explained all this to the doctor and he says, "sounds like colic". He's perfectly healthy and gaining weight. But I really don't think it's colic. Plus to suddenly start this at 8 weeks? Idk it just doesn't seem right. Has anyone else had this problem or dealt with something similar and it resolved itself soon?

Also, family had suggested that he's been overstimulated, possible ear-infection, or overfed...