Be very careful with aloe vera gel. I know some people swear by it, but if you do enough research, you will find out that aloe vera is actually a DRYING agent. I used aloe vera gel off and on last year, and every time I did I couldn't figure out what I was getting more dry. I blamed my soap (Purpose), and would slather MORE aloe gel on to stop the dryness. It never worked, and then finally someone explained to me what aloe vera gel actually does.
It will NOT help heal marks/discoloration on your face. Only time will do that, and since you are on Accutane, you need to MOISTURIZE, not use anything that will dry you up more. Let the Accutane do it's thing and eventually your skin will take care of itself.