Hoping for a Guide to nasty rough chemsex

Me and my girlfriend are very into nasty, rough sex: hard, degrading, aggressive fucking and somewhat long sessions (not the main point). MDMA worked great for us, especially on the comedown where everything functioned perfectly without adding anything else. Cocaine is mentally exactly what we like (dirty, aggressive, horny) but physically it caused problems. Even with sildenafil my dick sometimes didn’t work. My heart would race, I’d get anxious, feel like I’m about to explode, and once that starts the erection is gone, even though I would describe myself as fit and sportive. Sober sex can also be limiting because of my size, so most of the times i have to hold back to have sex in general unless she is very relaxed(and yes our foreplay is extensively long). A bit of wine helps to start things and roughen it up a bit....also reduce fear of hurting her, but it’s not the same animalistic intensity. We’re looking for best practices and hopfully chemguides/tipps on how people keep rough, dominant, nasty chem sex without anxiety, heart panic or shutdown, and what actually helped vs turned out to be a bad idea. I also read about stuff like GHB, Ritalin, 3-MMC, but info feels very fragmented. EU perspectives welcome.