I'm sorry your experiences with marriage have been so negative, because God didn't intend for our marriages to be this way. He gave marriage to us, and He meant for it to be a source of happiness and security, not conflict and discord.
Why do so many marriages go wrong? I've asked myself that question countless times, and I know there can be many reasons—from conflicts over money or intruding relatives, to issues like unfaithfulness or alcohol. I find many marriages collapse also because the husband and wife don't really try to solve their problems, but think divorce is the answer (which it isn't).
But beneath them all is a more basic problem—and that is the problem of our hearts. Down inside, we are self-centered and want our own way—and when two self-centered people get married, conflict is almost inevitable. This is why we need Christ, for only He can change our hearts and show us the meaning of true love. Jesus said, "Love one another. As I have loved you, so you must love one another" (John 13:34).
Don't go down the wrong path any longer—which is what you'd be doing if you ignored God's command to avoid sexual immorality. Instead, open your heart to Christ's forgiveness and love, and trust Him to lead you in the future.