There's absolutely no reason you can't be LGBT and a Christian. Anyone to tell you differently is simply mistaken.
Leviticus 18:22 is the most often cited verse by people clamoring that homosexuality is a sin. But, if you'll flip the Bible open, look up that verse, and read the stuff *around* that part, you'll see similar prohibitions against cutting hair, tattoos, shellfish, having sex while on or a week after one's cycle, and wearing clothing made of two different materials. If someone is calling you sinful for being LGBT, if they've ever eaten shrimp or had a haircut, they're just as "guilty" as you, and a hypocrite to boot.
Leviticus as a book is translated as to mean "For the Levites," which were a sect of the ancient Jewish priesthood. Arguably, it's not applicable to modern Christians in the slightest. We simply pay no heed to it, for the most part. I think you'll be hard pressed to find someone who's going to argue against haircuts and polyester blends. People pay special attention to Leviticus 18:22 because it serves to cloak their own bigotry in a religious garb. That's all it is.
Don't let their convenient selective fundamentalism get you down on the church. They're twisting the Bible to suit their own purposes. It's on the individual(s), not the religion.
Hugs,
Harley