1.Also is there's like a certain number of times I should shoot for?
2. What do you do if your 1SGT or commander doesn't want to sign off on your sick call forms?
Are you about to get out? I'd tell them that I'm trying to get fully checked out before I get out. If the Doctor concurs then that's all that matters.
As long as you aren't malingering to get out of a deployment it shouldn't be any skin off their nose. They're doing the same thiing.
If they straight up deny you and it's not affecting work I'd make an IG complaint.