The first thing you need to do is get a physical from your physician and explain these concerns you have to him or her. This will rule out any biological or chemical issues that may be depressing your sex drive. Be frank with your doctor, and ask him how you can have a more normal sex drive.
There are lots of things that can make you uninterested in sex. Some of them are excessive stress in your life, being tired, and taking certain medications like anti-depressants. If any of these sound like they may be part of your life, see if you can remedy them by reducing stress, getting more sleep and talking to your physician about your medications and it’s possible side effects.
If you pass all those hurdles, and still feel like sex isn’t interesting to you, you may want to try slowing things down in bed. You need to communicate this with your boyfriend because this is a mutual project. Allow your sex life to become less goal oriented and more process oriented, in other words, focus on more on play in bed, and less on reaching orgasm. Sometimes the race to the finish line causes you to miss all the gorgeous scenery along the way!
I hope this helps. Let me know how things go. 🙂