I have issues with my prostrate, and I no longer produce semen. Is it permissible for me to have a dry masturbation?

Shalom There is no problem with wasting seed for someone who does not ejaculate sperm. However there is a separate prohibition of masturbation that is valid regardless of whether one ejaculates. Kol tuv The source for this is the Gemara in Niddah 13b that masturbation is niuf beyad, adultery with one's own hand. See Igrot Moshe Even Haezer I 70 who explains this as a separate prohibition to masturbate regardless of ejaculation