I found a general long covid protocol on https://covid19criticalcare.com/ I didn't have all their recommended things to take, but I took the ones I could or had on hand without going to a doctor. But I also do a number of other things already recommended in the protocol by default. Such as Daily intermittent fasting, vit D, and regular doses of NAC with breaks here and there. lots of the usual things.

As far as a tube goes, it really just depends on the dosage you take. I remember there was a conversation chart a while back to dose it correctly for the weight that I no longer have. If you find a doctor willing to prescribe it that is definitely the way to go through.