Over half of the world's people with HIV live in Eastern and Southern Africa, a region stretching from Eritrea down to South Africa. 19 million in total, making 7.1% of the region's population. 59% of the people in this area living with HIV are women. Tracking new HIV infections shows that 6% of them are accounted for by men who have sex with men, meaning 94% of HIV infections are nothing to do with homosexual men. Sex workers make up 4%, their clients and related people 9%, people who inject drugs 2%.
It is very difficult to provide treatment to the population of men who have sex with men on account of widespread societal homophobia, which is a big part of why HIV is more prevalent among them than the baseline. Research in Western countries has shown that reducing stigmatisation of homosexual behaviour produces marked improvements in the health of the population in question
You can quote all of the statistics you want to. It wont change how the virus spread.
Anything that can cause harm about sex outside marriage can also occur within marriage. Rape, disease transmission, abuse, physical damage and so forth can all occur within the context of a marriage, while sex outside a marriage can be totally loving and consensual.
Irrelevant. Adultery does emotional harm to the innocent spouse. The things you mentioned will not change that.