Is it a sin to have homosexual sex and then repent? Will I be forgiven for my terrible mistake?

Yes / no if you shake it off, you are saved, and, if you end up acting on it, then, you are sinned BTW, not acting on it count as good deed, can explain it to you.

There is NO such thing as sin. Sin is an Illusion. Nobody is a sinner, even gays, fornicators, murderers or rapists.

Sin is a man-made construct created to CONTROL humans using fear.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.