Well, you're going to get at least slightly different answers, depending on who you ask.

My response is that what is known as the unpardonable sin is denying the Holy Spirit. This basically involves turning from the truth, rejecting Christ and "crucifying Him afresh," once you know with certainty that He lives. It's nothing less than willful and open rebellion against God, while having a perfect knowledge that you're doing so. Those who have sunk to this level would ascent to the crucifixion of the Lord all over again. It's the sin of Lucifer and his followers, who were cast out of Heaven. Since then, they've been known as the "Sons of Perdition."

It's important to note that it's virtually impossible for the "rank and file" believers to commit this sin, to say nothing of non-believers, because few have come to this level of knowledge. And this only comes to a relatively select few who, during their lives, live worthy to obtain what is known as the "Second Comforter." The Holy Ghost is the "First Comforter." The Second Comforter is nothing less then Jesus Christ, Himself, appearing to a person and the Holy Spirit witnessing to them that Christ indeed lives and is the Son of God. Once this happens, that person now has a perfect knowledge and is no longer going by faith alone.

To answer your question, gay people have the same opportunity to "get to Heaven" as anyone else. And that's by obeying all the laws and ordinances of the Gospel. This would obviously include accepting Christ as their Lord and Savior, as well as abstaining from homosexual behavior. Jesus said, "Strait is the gate and narrow is the way that leads to eternal life, and few there be that find it." He asks all of us to conform to His prototype. He has prepared the way to return to Him and His Father but it has to be His way.

As for "going to Hell," my understanding of all that may be quite different than many Christians. The idea of sinners being sent to some fiery pit to suffer for all time is not consistent with a loving Heavenly Father. There certainly is a Hell, and unrepentant sinners certainly will visit it, but only until their debt is paid. They will have to suffer the "buffetings of Satan" but all except the Sons of Perdition will eventually be redeemed through repentance (made possible by the Atonement of Christ). Now, this doesn't necessarily mean they will enter Heaven in terms of where God resides. But they will inherit a kingdom of some level glory, though they have no obtained the fullness of what they could have, and have their eternal progression blocked. This is what is actually meant by the oft-used term "damned." Their eternal progression is damned.