That's just the deal. Some people are born gay. Anyone who thinks we can "choose" what sex we're attracted to doesn't understand the nature of attraction.
Some are also born believing that they are in the wrong body for their gender.
It's not a "sin." And even if you think it is and cite one line from a huge document to back that up, aren't we all "sinners?" Why don't you cite the passages about adultery & lying also? Why the focus on homosexuality?
The reason we have things like "pride" month are because the LGBTQ community has been made to feel like they are "less" or even evil by so many, every day, for their entire existence. I don't think some understand what some of their lives are like, & being subject to hate, bullying and discrimination on a regular basis.
Life is hard enough. We need to support each other - not find ways to ostracize good people, and put hate out into the world for no reason.
‘I am gay – but I wasn’t born this way’
https://www.bbc.com/future/article/20160627-i-am-gay-but-i-wasnt-born-this-way
Is there a "gay gene"? Major new study says no
The 'Gay Gene' Is a Total Myth, Massive Study Concludes
https://www.livescience.com/no-single-gene-makes-someone-gay.html