Thanks for writing your query.
First of all I should inform you that taking MDMA is dangerous and should not be taken.
Mouth ulcers can be caused by a number of causes including some drugs.
You should take B-complex vitamin supplement along with local application of benzocaine
gel on ulcers to decrease the pain sensation. Gel should be applied about half an hour before meals. Avoid spicy foods.
Doing gargles with Betadine
gargle will help in curing any infection of the throat.
I hope this is helpful to you.