Generally, you take a small break. A week or so. Enough to enhance the horny, so to speak. Sex with someone else is fine though, in general, as anorgasmia during penetration is the biggest death grip side effect to begin with.

Then you come back (pun intended) with the usual process of reconditioning your brain to and nervous system to accept less intense stimulation by using less intense stimulation. If that’s via a toy, or by making sure to use plenty of lube along with gentle pressure and slower motion, you go as light and easy as possible.

Most guys I’ve known irl that dealt with it were usually on track by the end of the second week. Maybe not ejaculating yet, but either orgasming without ejaculation or getting close. Towards the end of the month, ejaculation starts happening quicker, and usually starts getting more intense as well. Sometimes it can take longer to get back to full intensity orgasms, but generally by a month or so, orgasm via oral sex or vaginal starts happening reliably. Anal a little sooner, if the guy likes anal at all.

In a pinch, prostate massage can help get past a barrier. Don’t want to overdo it and become reliant on that, but if you’re getting close and it’s just not working, it’s worth a shot.

But, that first week, no masturbation at all. You gotta give your brain a break so that it can both realign easier, and be more aroused from lack of ejaculation. I’ve never heard of ejaculation with a partner interfering. But I think I’d skip using a toy if it were me.

Now, I never experienced real death grip issues personally. I had been given access to good materials when I was younger, so I knew that going hard can cause problems. But I do have minor keratinization, and did end up struggling a bit in my twenties with finding the right balance to both reach orgasm by myself and not interfere with sex. So I can say that small breaks definitely help with both sides of the matter from direct experience. If nothing else, try skipping a day or two if a week is too much.