A book Aching Man recommended to me has a LOT of herbal remedies, vitamins, etc., that you might want to look into. I'm pretty sure you can find it at a local library... and amazon.com has a really great synopsis of this book, with a good many preview pages. I really think, especially in your case, you should take a look at this book.

Aphrodisiacs: A Guide To What Really Works

Author: Choueke, Esmond
Reissue; Paperback
125 pages
Published: November 1998
Kensington Publishing Corporation
ISBN: 0806519975

Corri