When you say that Homosexuality is an unforgivable sin, even after you are shown that Jesus, God Himself, said that all sins are forgivable except blasphemy of the holy Spirit, you are calling God a liar.
Thus you sin by accusing him of not being truthful.
What do you call it when a person claims God is not telling the truth?
I call it a sin.
One which you need to repent of.
So, for your sake, I will keep you in my prayers, with the hopes that you will see the error of your way by confessing to God that you are wrong and He is right.