The fact that his "bottom dysphoria is gone" is bewildering. Sure he doesn't have a dick anymore, but he doesn't have female genitals by any metric. He has a tangled mess of mutilated nerves and scar tissue, and it's completely non functional, not to mention agonising and trying very hard to kill him. If I suffered some kind of bizarre injury that destroyed my genitals, and I was told that I could either have the... thing... that he has, or a miracle procedure that would perfectly replace my genitals with that of the opposite sex, I'd take the replacement because functional and pain free is vastly preferable to dying slowly of sepsis and urine retention. How can he look down at his rotting, horrific wound that in no way resembles what it's supposed to be and say, "This is better than having a dick?"
Make it make sense.