MDMA can induce anxiety. Depending on the person and the stress he is conflicted with, it probably worsens the symptoms. Psychosis is such a random classification. Mostly everybody has some type of psychosis in his/her life. But most people rehab and learn from their mistakes. If you know the reason for your fear you have to stand up tall and solve it. If you are scared to get permanently dumb through psychosis, you are wrong. After solving your problems the "dumbness" and most of all the other negative effects will diminish. You should look out for a good psychotherapy if you don't get better yourself.
The sleeping problems should get better with time and anxiety can be part of the reason. As far as pemanent damage goes, it is a fact that you will suffer low permanent impairment with verbal memory recall depending on the total dosage of MDMA used over your lifetime (record says >10 times). Cannabis tends to impair learning permanently. Actually most drugs tend to impair your brain in some ways, but you have to be a hard core user to get to the point of no return. In most cases everybody can rehab with time. Some people are more sensitive than others and therefor feel changes more easily. You will be fine! Stay strong!