I am 21 years old. I was born in a Christian family and brought up with Christian morals. At the age of 19, I fell in love with a guy in my assembly who wanted to marry me. We started dating. After a few months we fell into a physical relationship, and I gave him my virginity. One year later everything went wrong between us and we broke up. I could not believe this was happening! He was the first guy I loved; I gave him what I valued the most. He, on his part, got engaged to someone else. This almost drove me crazy so I started flirting with other guys, so I would not to be frustrated at the end of it all. I found myself having sex with two other guys! I asked myself where those Christian values have gone? I'm so ashamed of myself. I can't even look myself in a mirror. I feel horrible about myself.
A few weeks ago the first guy came back despite the fact he is engaged to someone else, and I could not stop myself as I fell into sin with him again. I don't know what to do. Each time he comes I'm unable to stop myself from sex.
I've just placed God in one corner of my life.
There are two aspects in your life: What you intend to do and what you actually did. Just because you know the right thing to do, it doesn't mean you always follow through with it. Paul talked about this problem: "For what I am doing, I do not understand. For what I will to do, that I do not practice; but what I hate, that I do" (Romans 7:15). To fix this problem we have to get the two opposing sides of you to work together, and that can only happen in Christ. "O wretched man that I am! Who will deliver me from this body of death? I thank God--through Jesus Christ our Lord!" (Romans 7:24-25).
One problem that you face is that just because you were brought up in a Christian home, it doesn't follow that you personally have accepted Christian values. I noticed that you avoided calling yourself a Christian, and in a sense I'm glad you don't really see yourself as a Christian while being involved in fornication. I want you to become a Christian, but with that comes a radical change in your behavior.
A friend of mine just recently wrote an article that is perfect for your particular situation. I want you to read: "What Boys, Girls, and Their Parents Need To Know." What I hope you get from that reading is that men and women do not see sex in the same way. Let me illustrate it with something you said: You mentioned that you gave the young man what you valued the most, your virginity. The harsh truth is that your statement isn't true. You thought of your virginity as valuable, but you gave it away for free. I suspect that when you decided to have sex with him there were already small signs that the relationship wasn't stable. Like most women, you thought that giving him your body would make him desire you more and stabilize your relationship. For a while it appeared to have worked, but the real problems weren't addressed and they continued to get bigger until the relationship ended. Meanwhile, while your boyfriend enjoyed the sex, he didn't value it. Few people value what they don't have to work for. So he went off for new excitement and new conquests.
You foolishly thought to make your ex-boyfriend jealous. If he could get another girl so quickly and become engaged, you thought you needed to get another guy. At the time you still had not figured out that doesn't hold any guy, so you repeated what you did before -- only more quickly and without any foundation in the relationship. You ended up with two guys who love to use you for sex, but whom you really don't care about, nor they you. Take a moment and read Marriage's Glue to see why what you had hoped didn't work.
Now your former boyfriend is coming around again. Perhaps word got out that you are willing to have sex with just about anyone. But I suspect it is more that things are not going well with his current girlfriend, but she won't let him have sex with her. He figured you would be willing, so he can take the edge off his desire for sex with you. And since you know he is engaged to someone else, he doesn't feel the need for any commitment or obligation.
Let me put it bluntly: you made some major mistakes, but your ex-boyfriend is a selfish, manipulative cad.
So what can you do? First off, dump the ex-boyfriend. While he might be fun in bed, he will make a horrible husband. After all, he is cheating while he is engaged, so what do you expect will happen after he is married? I can tell you; he'll be committing adultery and frequently. Second, dump the other two guys. They were willing to commit fornication without really knowing the woman they were having sex with. Their focus is all wrong. Third, no more sex until you are married. You want a man who loves you so much that he treats you with honor and wants to earn the right to your body by first committing himself for life to you by marrying you.
You've convinced yourself that you, as a person aren't that valuable, so you are using your body as a lure. It is completely the wrong way to think. You are very valuable as a person. Anyone who wants your body has to first prove that he wants you. (And no free samples!)
In order to see your full value, you need to get yourself right with God. He'll give you freedom from your past sins. "Do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God. And such were some of you. But you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus and by the Spirit of our God" (I Corinthians 6:9-11). Take some time to learn How to Become a Christian.