I think it is good you have started the co-supps first, I have a few questions/input.
"magnesium (when I can tolerate it)". How often can you 'tolerate it'? what type? I've never had problems with it but I know others have. This is an important mineral, find a way to get it in there. What form are you using? How much?
"Celtic salt where ever I can force it,". I've played around with different ways of taking this, at different times of day, diluted in water or with food, etc. What I found works best for me is this: I take it first thing in the morning, mixed with the juice of a lemon and warm water, about 8 oz. I also put a full teaspoon in there. Your kidneys need this to detox bromide. Don't skimp. Find a way to get this on a regular basis, in the most tolerable form. I have come to enjoy eating it, but that's just me.
As for dosage, well, no one will TELL you what to take. We can't say what is best for you (e.g., slowly titrating up or jumping full in at a higher level). A conservative approach would be to increase it a little each day, keeping track of the amount and how you feel. Then you can decide for yourself if you want to jump up to a higher dose, which it sounds to me like that is what you are leaning towards.