A hotspot is like if you put a baseball cap on with the Velcro done up too tight. Multiplied by 100. And focused on a spot on your head, not all the way around. And you have to maintain a capacity to fly an aircraft whilst pushing through the pain.
Wearing in your helmet is a good idea because a hotspot will quickly become distracting. The key is when you're fitted, leave it on for a little while. If it's uncomfortable, tell them, and they should play with it and get it to sit better, Life Support Fitters are good at that. Don't feel like you're wasting their time or taking too long, it's important, and it's one thing you don't want to have to worry about whilst airborne because it will detract from you showing your potential.
Good luck