1. The Catholic Church has always taught that sex outside of marriage is a sin. It's not something new.
2. It doesn't matter if it's the 21st Century or the 1st Century - a sin is a sin.
3. Plenty of people get on quite will without having sex before marriage. You need food and water and warmth and rest, but you don't need sex to live. Sex is entirely optional.
4. Yes, a majority of guys will run a mile if you say no sex before marriage. That happened to me, too. And you know what? I finally realized that a guy who demands sexual performance from me in order to determine whether or not I'm worth his time is a CREEP. Those fellows were not worth MY time. I held out and married a man who was firmly committed to saving sex for marriage. We're very happily married now.
5. How do you know a relationship is "committed" unless you have publicly made the commitment? I mean, if a guy isn't willing to stand in front of his family and friends (and God) and say that he wants to be with you forever, he's not very committed, is he? And if he IS willing to do that, he's willing to marry you, so he should.
6. Jesus said a lot more than what's in the Bible (the Bible even says so in the very last verse of the Gospel of John), so you don't know that He didn't address this topic directly. It's a good guess that He did, though, since the Church He formed has always taught that all forms of sex outside of marriage are sinful.
7. A person only goes to hell if they don't feel sorry for their sins and the sins are very serious.
8. Yes, the Church condemns the contraception pill and all other forms of artificial contraception, because they interfere with one of the two key purposes for sex. The two are bonding between the couple and procreation.
If you have any more questions, please feel free to ask.