My experience with mixing mdma and weed was actually a terrifying one, which I'll never do again. Or if I do do it again, it won't be in the same environment.
So, this is how it all went down. A couple of friends and I decided to go to this music festival that's super low-key but has amazing vibes. We actually saw bonobo and Nicolas Jaar which was insane. But I would've enjoyed their sets more had I not been under the influence. Anyways, so this was actually my first time doing mdma so I was pretty nervous to say the least. I was surrounded by all my friends, so I felt pretty safe though. Whatever, the point is I took an mdma pill right before the sets. They said i would start to feel the effects after half an hour. We waited half an hour or so and decided that it might not have been such a strong pill, so we decided to smoke some weed. It hadn't been my first time smoking weed so I was totally cool. I didn't think much of it because everyone else had done mdma and smoked at the same time and no one had any serious side effects. It was 6 of us in the group and we all shared about 2 joints and 2 blunts. After about half an hour I started to feel this calming almost euphoric effect. It was AMAZING, everyone was feeling amazing, everyone was vibing, it was great. Up until we all decided to smoke 2 more joints. After we smoked the joints, almost immediately, I felt this insane pressure in my chest and my heart started beating like a fucking wild horse while my brain started feeling foggy and slow and I couldn't even fucking speak. I felt like I was about to die of a heart attack. My heart wouldn't/couldn't slow the fuck down and while I felt like sleeping because of all the weed I smoked, I couldn't stop moving. I had to constantly be on my feet, dancing or moving. Five times that night I had to walk outside to the fresh air because I felt like I was suffocating with all the people surrounding me. I almost passed out twice and felt like throwing up. It was a disturbing experience to say the least. Now, while I might've abused of the cannabis we took, I still don't recommend mixing the two. Weed tends to slow you down and your heart rate, while mdma does the complete opposite. But both have the same effect on your brain where it just fucks up your short term memory so that must be why you couldn't even hold a conversation for more than 15 secs. Anyways, hope my story gave you some insite on a more extreme case on the effects of mixing those two drugs.