The Catholic Church doesn't dictate what you or anyone else does, unless you want to be a Catholic.  If you don't want to be a Catholic, that's fine.  So, yes, only married couples should have sex (not sodomy), and they should be doing it without artificial birth control.  Notice the word, "should."  We can only do the best that we can when it comes to sin, and we should confess when we falter in our efforts to adhere to Church teaching.  But if you flat-out disagree with what the Church teaches, there are plenty of Protestant sects available to accommodate your desire to have guilt-less sex, that is, sex the way YOU think it should be.