This is it 🤣 Having said that, there are hospitals or Maggies centres that run local support groups and PCUK supports some of these - you should be able to find out via Google whether there is a group in your area.
PCUK was also running a face to face support group for gay, bi and trans men and their partners but I think that this hadn't met for quite a while, even before Covid.
You will find more relevant information on the GBTQ section of this forum, including other MSM who have been where you & your partner are. Some of the specific implications for you and your partner depend on whether he is a bottom, top or versatile. Some MSM find it a struggle at hospital or doctors appointments because medics may have no understanding of anal sex or why erectile dysfunction and the loss of the prostate is so significant to this group.