Mine had bronchiolitis when he was a baby. Terrifying the first time. Gets a bit easier once you know what to do, but that doesn't make it easy. You have my sympathy.
He got antibiotics for one bout of it because he was struggling with everything so much, they figured that if there was even a hint of bacterial infection anywhere, it'd be one less thing he'd have to fight.
We ended up with him on steroids quite a lot, too. We saw the Head of Paediatrics when he was rushed to A&E twice in a week. He guessed mine had probably had covid, but the tests aren't sensitive enough to detect it in babies/toddlers.
Lockdown when he was a baby meant he got all the bugs at once when lockdowns ended, rather than getting them gradually like they would in normal times. Head of Paediatrics at our hospital reckoned he'd seen a 400% increase in babies with severe respiratory issues. I doubt he's wrong.
Mine now 2.5 and has had some near misses with colds going nasty this winter, but no hospital admissions. It does get better, but that feels a long way away when you're in the throws of it. Make sure you have salbutamol and a spacer at home/with you when you go out all the time (even if hes not currently poorly). You won't likely have to use it, but if you're anything like me, you'll feel safer/better knowing you can give it to him if needed
Keep pushing, use your instincts. They'll be right. I found if you have to ring for an ambulance/when you arrive at A&E, tell them how many breaths/minute your LO is doing. (I counted mine with 30seconds and then doubling it) It'll give them a far better idea of how poorly he is.
Solidarity from one mum to another!!