Everything you have said is incorrect and I suggest you do some research.

Semen is 'good for women's health and helps fight depression' | Mail Online

Is Sex an Antidepressant? - Depression Center - Everyday Health

What does sin mean?

Also many animals do masturbate and eat their own semen after doing so. Homosexuality does happen in other animals, but I was explaining the reason why the bible states homosexuality is wrong and a sin.

Anyway, I don't want to take this thread off topic. The reason why most christians aren't accepting of homosexuality is because the Bible isn't and to christians, the bible is the word of God. They are not going to choose condoning homosexuality over God. Most christians don't hate or dislike homosexuals, just they don't condone the act. They are entitled to that opinion