Im very sorry youre so troubled…i can sense your pain and confusion. Just remember whether u are attracted to men/women/both or not attracted to sex at all…sex is to be used in the vocation of a Sacramental marriage between a man and woman open to the pro-creation of children.
Outside of that we are all called to be chaste (even in marriage).
There comes a time in ppls marriages where for one reason or the other sex is no longer possible. Take comfort in knowing that our natural state is not to be having sex in heaven. There will be no marriage in heaven.
Chastity even celibacy has many virtues as the person alligns themselves with higher reasoning and less of the lower faculties.
In the future u will have to do much soul seeking like anyone else to find out if marriage is the vocation God calls u to.
If u are homosexual u can live a joyous celibate life. Just as the never married/divorced without annulment are called to do.
Also…remember the conditions of a mortal sin
- Grave matter
- Full knowledge
- Full consent of the will