I CANT CHANGE MY BRUSH

[#1]

I can't find any resoloved questions regarding this so hopefully someone can help me ahh

My new art has basic appearance thing is off but I once I start drawing my pen immediatly goes back to basic. Sometimes I can't even click on the brush to change it. Please help I have an art project due tomorrow

[#2]

I can't find any resoloved questions regarding this so hopefully someone can help me ahh

My new art has basic appearance thing is off but I once I start drawing my pen immediatly goes back to basic. Sometimes I can't even click on the brush to change it. Please help I have an art project due tomorrow

[#3]

1. What do you mean speaking that you can't even click on the brush? 

2. Can you apply the brush after creating the line?