You may not have had sex in a while, because of your busy lives. You are too tired, and while you miss sex, sleeping is just that much more appealing. How do you know when this becomes a problem and you need therapy to reconnect with each other? Well, that all depends.
Are there underlying psychological problems that are contributing to your not having sex. Is it simply that you are busy, or you make yourself busy to avoid sex? If you think there is something else going on underneath the “I’m too busy” façade then it might be time to see a therapist. You specifically should see a sex therapist. You should be prepared to talk about your sex life, a lot. They are going to want all the details, you won’t be inappropriate just more honest then you might have wanted to be. It’s okay to open up to her, or him. They are there to help you and are just trying to get an idea of what is really going on between you. You may feel uncomfortable if you aren’t prepared. The therapist also might have you read books and talk about things with your partner outside of therapy. If you really want to make your relationship work, then it should be a problem no matter what she asks you to do.
So what will a therapist help you and your partner with? Sex therapy is for a lot of different things but it is definitely for helping you express yourself to your partner sexually. They will help you with arousal, painful sex, relationships built around sex, and communication to name a few things. They aren’t magic makers, but if you are really struggling in your sexual relationship then you may need therapy, and there is nothing wrong with that.