Just to update, it seems the burning starts 24 hours after my dose of Methotrexate and lasts on and off for about
3 days. It's not just mild burning, it's like the kind where of you're chopping onions your eyes water and you can't keep them
open. I was driving today and had to pull over because I literally couldn't see. I'm waiting to hear back from the dr; IDK if he'll care or not but in case this happens to someone else it seems it is from the methotrexate dose.