Snorting substances for prolonged periods
can cause damage to the mucosa (or the lining) of the nostrils. Sinuses
are closely related to it. Rubbing on gums repeatedly again can cause it damage. MDMA has varied effects on the brain, it can affect your attention, memory, learning, it can cause other psychiatric and behavioral changes as well.
There is nothing to be embarrassed about. Most of your complaints would have been dealt earlier with by professionals in other patients who seek help from them. What is more important is that you have to be prepared to want a drug-free life. And i think you have sufficient reasons to want to quit again.
Wishing you the best of health,
Dr Anjana rao