G'day mate,
If anything I'd say the continuous use of MDMA caused your problems here rather than some amphetamines or other chemicals, not that they would have helped but I think if you were rolling once or twice a week, the problem would be lying with MDMA.
You should only really roll once a month, it's good that you've been off for three months though, that's a great effort to go from weekly to a few months sober, keep up the good work.
No party drugs will lessen your chances of your anxiety increasing, if anything they are only likely to develop more to the problem, IME.
Give it some time before using again, but there's no problem with using once in a blue moon if you absolutely have to. Don't think yourself as a failure or anything, so long as you don't go back to rolling weekly, maintain a healthy lifestyle with good food and exercise, your anxiety problems should eventually start to clear up (not accounting for external IRL factors), but biologically you'd be on the right path.
Good luck mate wishing you all the best.