Hi all,

I am in need of some help or guidance.
My adult Rosy boa Atticus (5-6yrs) has always been one of the most docile, laid-back, basically sweet snakes I'd ever met. (I haven't owned him his whole life but over a year) Even when I got him from a pet shop with crappy care and he came home dehydrated and full of mites, he was sweet during treatment. Well, he's not anymore, and I can't figure out why.

I am at a loss right now. I love this snake and do not want to re-home him, but I feel if I can't figure out what happened, I may have to. I don't want to keep a snake that I can't provide enrichment to, or that I can't handle. I don't want him to live his life in his enclosure doing nothing.

This year he went off food for a while, which I know can be normal, but I'm a worrier and took him to the vet after 3-4 months of his food strike.
The vet didn't have anything super conclusive, he had no symptoms of an RI, but one of his lungs looked slightly less clear in an x-ray than the other.
So she gave me antibiotics to give him. I did, and he began eating again a couple weeks after he finished them.

Then it was literally like a switch flipped in him. He started being nippy, trying to bite, super defensive. I thought maybe he needed more handing and took him out for 15min 2x a day (between digesting meals of course.)
It didn't help or make any difference. I got some reptaid to give him as it helped my sister's rescued water dragon a lot with his health.

Atticus seemed to calm down a bit with a week of that, put some weight on in a good way. I handled him very briefly yesterday with gloves on and he seemed fine. Although weirdly kept wanting to slither toward my face.
Tonight, I was talking to him while he was in his enclosure, which he used to seem to enjoy. He wasn't acting tense or getting into a striking position, but out of nowhere launched himself at my face through the glass.

I'm very depressed at his sudden behavior switch. He was seriously my snake ambassador for people who are scared or unfamiliar with them.
I cannot figure out why this happened.
Was it the antibiotics? Did they mess up his gut biome too much? He seems to have a weird tic after them too.

Any insights would be appreciated, but please be kind. I can't handle much in the way of negative or rude comments. I'm trying my best. I have multiple health issues and autoimmune conditions, some of which came out of nowhere this year and I had to quit my well-paying job for something that is barely income, and move in with family members, so going to the vet again if that is necessary would be something I have to save for. Not that the exotic vet available instilled much confidence either.

Sorry for the lengthy post, I appreciate any who made it this far and may have some insight. I just want to help my boy.