Or, you could go to the interview if it’s scheduled before Jsnuary and find out if, in fact, you have a ban. If you don’t, and everything else is good in your case, you’ll get a visa.
If you do, they will give you a 221g refusal until either a) you get a waiver approved, or b) the ban is over. You do not have to apply for a waiver just because you went to the intervie. You can still wait out the ban, which will overcome the 221g refusal much sooner than getting a waiver, and the visa will be issued. You might have to update your medical; however, that’s likely still cheaper than the waiver fee.