Plaster is loose, itchy and smells?

Hello,

I've had my leg in a cast for almost four weeks now. It goes from my toes to mid-thigh.

Problem 1:

Initially, my leg was swollen, but that has subsided now, and there are large gaps between the cast and my leg in places. Is that bad? I haven't had to change the cast yet, and there probably won't be. I'm supposed to wear the cast for six weeks.

Problem 2:

The cast smells really bad. If you get close to it, you almost want to throw up. It's been getting worse lately, and I'll still have the cast for over two weeks 🙁

Problem 3:

It itches terribly under the cast. I don't know why. Is this serious? What can I do?

Problem 4:

Starting next week, I'm supposed to spend the last two weeks walking with crutches if possible. Until now, I've been in a wheelchair all the time and have barely used them. Why is that? Do you have any tips?

Thank you in advance

Julius