New medicine

As I mentioned in my last post, my PCP put me on another drug to go along with the Lasix.
It is IC Metolazone. It's a 2.5 mg tablet.
I have gone from 250lbs last week to 239lbs today. I really hope it keeps working. I need to lose all this excess fluid.
My PCP also called this morning to check on me, because I guess there are some similarities to Sulfa, which I am allergic to, in the new drug, and she wanted to know if I'd started taking it yet and make sure I am okay. I have been on it for a few days, and don't seem to have any allergy-like symptoms, so that is good.
I know that this can cause a potassium drop, so I am trying to have things high in potassium to avoid that.
I got a letter from the diabetes nurse telling me that my Vitamin D level is very low. (despite the fact that I am on Vitamin D daily) and sent a script for a weekly dose, which is higher.
I am going to call my PCP on that to figure things out.