What did the doctor say about how to help the burns? The aloe vera will help a lot but I'm not an expert. I think the scars will go away with time.
We'll always have stress in our lives...sometimes a lot of stress. You'll need to find a way to cope with all the stress. Do you have family or friends to talk to? Maybe go to a counselor at uni which should be free.
Understanding how to handle stress is important. If you're in a stressful situation that can be changed then change it, but sometimes you have to tough it out.