While it is ok to ask for some advise here, you need to speak with a hair restoration specialist. Accutane can cause hair loss. These medications need to be monitored.
You would certainly require more than 2000 grafts for a meaningful transplant. If you undergo 2000 grafts, you would set yourself up for having to commit to having more transplants to avoid looking odd as your hair loss progresses. It is best not to have a transplant at all in that scenario....
These hairs will sooner or later shed. They are never a problem for new hairs that start to grow. Usually, there is a lag time between the time the hairs shed (2-8 weeks) and the time the new hair grows (3-8 months). IF for any reason, there is an overlap between the two, pay no attention to it...