You seems to have what we term as Hypoactive sexual desire disorder, which is a multifactorial disorder. Androgen deficiency is an important, treatable cause of hypoactive sexual desire disorder, and it should be excluded by measuring serum total testosterone levels. Other causes can be systemic illness, depression and other psychological problems, or relationship and differentiation problems. Couple counseling is a part of the treatment but if you have other psychological reasons, they should be handled by your physician appropriately. In any case a blood work for the androgen should be done. If you have, associated erectile dysfunction also, these would need different tests.
The treatment would entail;
1) Selective PDE5 inhibitors are safe and effective (sildenafil, vardenafil, and tadalafil)
2) Vacuum Devices for Inducing Erection
3) Intraurethral Therapies
4) Intracavernosal Injection of Vasoactive Agents; people can be taught to give the injection.
Please feel free for your follow up questions.