What happens in the office of a sex therapist?

What does it mean about our relationship if we need therapy? What if the therapist tells us our issues are unfixable? Shouldn't we be able to fix this ourselves? What if we start going and our therapist just wants us to come back over and over again for years? How do we know when we don't need therapy anymore? Are they just going to make me talk about my feelings? How do we even figure out whether or not our struggles are worthy of a therapist?