There are many outlets for professional relationship advice these days. Couples can go to marriage guidance counsellors or couples therapy professionals for assistance with rebuilding their partnership. This is available to all sorts of couples as well as people who are in unconventional relationships which may involve more than two people. There are a number of self-help books that you can read which will offer insights into your relationship and some a designed to be read as a couple so that what they reveal is learned by you both. If the problems in a relationship are of a sexual nature, then seeking the professional help of a sex therapist may be appropriate.