I found myself in a similar state after abusing MDMA myself. It's not a pretty place!! I'm so sorry to hear you're having trouble. We are here to help.
So, I can't say that I've ever tripped specifically to 'reset' my mental state as a result from MDMA after effects. However, I can say that I have had the world's scariest and traumatizing experience in my head while rolling my face off and taking hits of computer duster.. 8) ...and I felt like I did serious damage to my brain, because I was in the darkest place imaginable for nearly a year after. I was a completely changed person. After that, I avoided MDMA like the plague, I feared it, and had actually never tripped on any psychedelic besides salvia at that point either. Eventually I came across some 2c-e, had my first couple psychedelic trips, and felt like I had a new interest and understanding and respect for both drugs and my own mind and didn't need to fear them both so much, nor did I need to dwell so damn hard on what the drugs I've taken *might* have done to my brain. Soon thereafter I eventually found an MDA/MDMA mixture and took that a handful of times, all with absolutely fantastic, glowing, euphoric, visual experiences that would leave me feeling even BETTER than I did before. I noticed, oddly enough, that every time I took that MDA, I would feel less 'damaged' from that one MDMA+duster experience in the weeks following the MDA roll. I would also feel a similar 'enlightening' after mushroom or 2c-e trips, as if I was 'moving on' that little bit more from that traumatizing, life-changing experience I had a few years ago.
So, I don't know if this answers your question, but in short, yes I feel like a good mushroom trip might aid you in moving past your post-MDMA depression. I'd start with a low dose though, and work your way up. If by chance you end up having a bad trip, you don't want it to be an intense one because it could seriously mindfuck you in the sensitive state you're already in. Treat your mind and brain like a broken leg at this point. You need to be rolling around in a wheel chair or using crutches, putting your leg up, resting it, nursing it, not putting too much pressure on it, let it heal, and you'll be back out there running touchdowns before you know it.

It's just another body part, it heals, it moves on, surprisingly resiliently too! Take vitamins, eat good food, get rest, sleep well, exercise, drink lots of water, avoid drugs, and involve yourself in activities with others that do not involve drug use or anything that reminds you of MDMA.
After rolling a few more times, getting into and out of opiates, trying this and that, I eventually put MDMA on the shelf again and didn't touch it for a very long time simply to allow myself to recover completely. Eventually, I finally got to a point where I can honestly say I've moved on and don't feel like I have damaged myself and that I am perfectly ok with saying goodbye to MDMA and never touching it again. I can say that I'm happy, and mean it. Once at this point, and have been there for a while, I decided one final book-closing roll was in order, especially seeing how I had a little bit of very pure, tested molly left. So, for Valentine's Day, my girl and I planned a stay-cation in downtown Seattle, book a sweet hotel, went to a cool techno show and dropped a cap of this molly, both of us with the understanding and intention for this to be our last and final experience with MDMA forever. It was a very subtle roll seeing how my girl and I had to split ~150mg, however it was smooth, fun, enjoyable, and we had a great weekend with each other after that night. We both agreed that we felt good about closing the casket on MDMA and there's a real special feeling that I can't describe, but it's almost like the feeling you'd get the day that you can finally honestly say you're over a girl you've been heartbroken about for years.
You're not permanently damaged. Just keep reminding yourself of that. It's very rare that someone sustains permanent, irreversible brain damage from MDMA use. Hang in there man!!
Keep us posted.