A friend of mine proposed to his wife with the following quote from St. John Chrysostom:
"I have taken you in my arms, and I love you, and I prefer you to my life itself. For the present life is nothing, and my most ardent dream is to spend it with you in such a way that we may be assured of not being separated in the life reserved for us. I place your love above all things, and nothing would be more bitter or painful to me than to be of a different mind than you."
This is perhaps my favorite explanation of love, that the man who loves a woman wants heaven for her more than anything. No pleasure on earth could outmatch his desire to be with her for eternity.
I'll surely grant that the idea of abstinence is pretty boring. It means "no sex." The idea of purity is different. It means love. It means wanting nothing but heaven for the one you love. It is the highest form of human love, because it requires sacrifice. It's a participation in the very love of God. Any animal can have sex. But how many creatures can be pure? Only the ones made in the image and likeness of God.
I hope though this you see that I'm not trying to snuff out your love for another person, but to ignite that love.
You had mentioned that you knew the consequences of sex, but have you thought this out fully? For example, what if death is not imminent, but you become pregnant, give birth, and then die and leave a child orphan? Or what if you live and the father dies? Either way, the child's memory of his parent is that she knew she was going to die, so she preferred sex, regardless of the consequences in this life or the next. What about if you do not die soon, but your partner does? Where does this leave his soul? What if either one (or both) of you lives, and then goes on to marry another person? What about the heart of that person's future spouse?
In high school, several of my friends died. Through their deaths, I learned that we never know how many days we've been given, and we should love to the fullest with the time we have. But this love must have eternity in mind, not just the passing pleasures of this life. While sex right now might seem like an oasis in a desert of suffering, I promise you that it is a mirage. It promises everything, but does not deliver. That's why nearly 80% of teenage girls regret losing their virginity. You sure don't hear about that statistic on MTV.
So, the answer to your suffering is not to throw caution to the wind and indulge in whatever you want. The answer to suffering is to realize its meaning. One of the greatest saints the Church has ever known was a man named Padre Pio. He said, "Suffering is a gift from God. Blessed is he who knows how to profit by it." Lest you think he didn't know what he was talking about, he suffered terribly for decades, and lost a cup of blood every day for 50 years!
During that time, he had every reason to drown his pain in pleasure. But instead he immersed himself in the love of God and grew in wisdom and irresistible joy. So, with whatever days you have left, give them to God and he'll give you greater delights in heaven than you could ever have grasped on your own. Then, if you die, your eternity is secure. And if you live, your future is wide open. Either way, you win.
. National Campaign to Prevent Teen Pregnancy, "America's Adults and Teens Sound Off About Teen Pregnancy: An Annual National Survey," (December 16, 2003), 17.