You should marry because you've found the person you want to live the rest of your life with, not because you want sex.
If a believer finds it is too difficult for him to go his entire life without having sex (or even a year or however long) he should marry. Wanting to have sex is a reason to choose marriage over celibacy. Or at least, wanting it so bad that celibacy is too daunting of an option. Some people are fine with celibacy for life.
I was a virgin when I got married, but I knew I wanted to get married, too.
As far as WHO one should marry, having sex isn't the determining factor. Most people are capable of having sex, but grabbing the first person of the opposite sex who walks by and proposing marriage isn't wise. A believer need to marry a believer, and there are a lot of traits to look for and traits to avoid. Proverbs has lots of advice about this, especially for men looking for wives.
In the old days, parents might say, "This is who you will spend the rest of your life with." I think we've made getting married a bit hard in our culture. Media presents young people with an ideal of beauty that is hard to attain. Our culture pushes dating on young teens with no expectation that dating is supposed to lead to marriage. At a young age, children are taught by their peers to use rather meaningless criteria for choosing a boyfriend that don't really translate well into good criteria for marriage (popularity, e.g.). Dating and breaking up trains young people for short-term relationships and divorce. In the old days, parents and other relatives might introduce prospective marriage partners. That's considered rather uncool in our culture. Shy individuals can go for decades without marriage without any help from family members. It's hard to find someone.
And people in our culture are programmed with these Disney ideas of what it means to be in love, and that if two people find love that they will magically live happily ever after. And some young people think they are supposed to feel a drug high from hormones in their body for the rest of their life if they are 'in love' and when it subsides, they may decide to look elsewhere.
It is not wrong to marry as long as one marries one who is Biblically eligible and does it in an honorable way. If two Christians meet one day and decide to marry, as long as they don't violate the teaching of Scripture, that's perfectly fine.
We all need to learn to resist temptation. After you get married, you have to resist the temptation to have sex with people other than your spouse.
Sure we do. But having a spouse to have sex with and have that intimate bond with sure does take the edge off temptation. There is no need to look for someone anymore.