I wish I could tell you that your circumstance is new, and one that I’ve not seen or heard of before. Unfortunately, it is becoming more and more common.
The first thing I would say is that even if your husband has homosexual desires, this does not require him to live a homosexual lifestyle. After all, there are those who chose to be single, and this means that they must deny their heterosexual desires. Your husband appears to want to live a homosexual lifestyle; otherwise he would remain married and deny his homosexual desires.
Does your husband profess to be a Christian? If so, then it would seem that the process of church discipline is in order (Matthew 18:15-20). This could be done by a group of believers, even if your husband does not attend any church. They could confront him and urge him to turn from his sin.
Are you actively involved in a local church? You really need to be. You need the fellowship, teaching, and support (Hebrews 10:23-25).
If your husband takes up the homosexual lifestyle then many, including myself, would be inclined to believe that you are eligible to re-marry. These are difficult matters. Ultimately you must study the Scriptures that are involved and come to your own convictions, knowing that other Christians may disagree with you; some may look down on you for remarrying.
If we were living in Old Testament times, your husband should have been stoned, and then you would surely have been eligible for marriage (Abigail becomes eligible to marry David when God takes the life of Nabal, her husband – 1 Samuel 25).
Here are some articles or lessons on the BSF Website that deal with the subject of divorce:
The major divorce texts that you should carefully consider would be:
1 Corinthians 7 (all)
I believe you are right when you say that there is no way that you can prevent your husband from divorcing you. (In some ways, this may protect you from some of the diseases he might carry, as a result of his sin.) If you conclude that your husband was not a believer, then I believe that you are clearly eligible to re-marry (1 Corinthians 7:15).
I can tell you that while the days ahead look very dark, I have witnessed many who have grown strong in their faith in the midst of circumstances similar to your own, and they have experience peace and joy in entering into a more intimate relationship with their Savior, as a result of their suffering. Again, you will need to support of a good church.
Philippians might be a great book for you to read and meditate upon.
My prayers are with you.