How long will it take for my toenail fungus to go away?

It's hard to say because everybody's different. Fungus stays around for a lot longer on some than it does for others. Your doctor should have a sound answer for you tomorrow.  

That's a question for your doctor tomorrow.

https://www.webmd.com/skin-problems-and-treatments/treat-toenail-fungus#1

If you're prescribed meds for it, usually about three months. If you're not or you don't take them, maybe never. 

3 months seems like a long time too, i gotta see a foot doctor too in about 2 wks

I have that problem, and the leaflet with the prescribed medication advised possibly a year.

I've also had a knee replaced, but although the surgeon and nursing staff needed to know what medicines I am on, the medication didn't seem to affect the surgery.