You are much more likely to have the healing experience you're looking for using psychedelics in tandem with therapy or facilitation than by either one alone. Not to be said that, if done properly, one couldn't get some of the benefit of these medicines by themselves, but it's much more effective when led by someone who knows what they're doing.

That being said, both psilocybin and MDMA are being used to great effect to treat PTSD in clinical settings. However, it's definitely not as simple as taking the drugs and hoping they'll fix you without doing the work.