I work in critical care here in the states so a few thoughts to maybe give some insight:
1) They likely tried non- invasive mechanical ventilation first (Bipap mask, etc) but you might have been panicking and too large to restrain. Intubation & sedation is only option. Likely factoring in is the perceived difficulty of the intubation. Large neck and "off-season " 
physique compound the difficulty of getting the tube past the glottis, so they may have opted to intubate while you were still stable rather than wait till you crash at 3am.
2) I guarantee they gave you some type of corticosteroid, be it dexamethasone, methylprednisolone, prednisone - whatever. it's standard of care for all sorts of acute resp failures. Would also explain why you're on so much insulin
3) 21 days vented is a loooonnng time. Be patient with the recovery process. The physical effects are easy to see-- weight loss, loss of strength/coordination --but psychological effects are easily missed or neglected. Covid patients are hard to sedate and you're pretty big so here in the states you would have received a heroic amount of narcotics. Our colleagues across the pond are a bit more judicious in their use but still: between the drugs, the disease state, and the plasticine hellscapes that are ICU rooms, delirium and other cognitive impairment is common in patients who survive the ICU. Be open to mental health care to hasten your return to normal.
Glad to hear you're ok, I've been a fan of your posts for 10 years now - back when you were KillerMuscle on ProM LOL. If you have any other questions, I'll do my best to answer them.
Thanks for the great reply!
As far as narcotics I know I was on fentanyl and midazolam.
Now on 40mg of oxazepam which I will start tapering down tomorrow. I'm at a rehab facility now and they will release me on friday. Today I walked around the hospital unassisted for the first time.
As far as mental sides I experienced the delirium, delusions and nightmares big time. It's amazing what the mind can conjure up and it all seems so real. I talked so much embarrassing baloney to family and staff. Now the staff say think nothing of it, we're used to it. They were also restricting my water intake for a while and it was hell, I was dreaming/hallucinating about large cold beers and cokes just out of reach.
Edit: Getbig was also featured in these waking nightmares. Ron had made Getbug a pay site and instituted new harsh rules against racism and bigotry.
This is the second time I experience this. From what I remember they didn't try the mask this time but with the swine flu episode they tried that but I was panicking just as you said, despite benzo injections. I suffer from anxiety as it is. Last time I was panicking in the ambulance already and begged for something to calm me down but they said they have no such things. I was begging them, "please have some compassion, I'm in hell" and they finally hit me with something.
I kinda knew about the corticosteroid/blood sugar connection but forgot all about it and didn't know I was probably on some steroids.
One weird thing that happened is that I now need reading glasses, as if my vision changed overnight. One nurse said vision changes are commonly reported by Covid patients. I don't know if there might be a connection. This nurse said she herself was sick from Covid for a year, extreme tiredness was the main problem.
Again, thanks.
