I can totally sympathize, as well as empathize with you. The emotional rollercoaster is a rocky one; nothing I'd wish on any other woman. My first bit of advice to you is, trust your gut feelings. They have not failed me yet. I love my husband and probably always will, and yes..he said the very same things to me. I do not know if you have children involved, as I do, but I feel that my H's defection is more detrimental to my children than myself.
My husband has put me, for the last month and one half on the rollercoaster of "I want to work it out with you", "You gave me all the important things", etc., etc., yet I too, find voice mail messages from the woman who is supposedly had "broken" it off with. The feeling is so painful that it consumes you. I know, and still struggle everyday. I try to be strong for my children, but often find myself making several trips to the Ladies' Room (during the work day) to compose myself from a crying fit. I would have been celebrated my 13th Wedding Anniversary in June, but I know my husband for over 15 years...I was just a young woman of 19 when we met. We have two healthy, intelligent and loving children together, but he has forsaken them as well, for the love of this woman. My feelings are this, if he loves her that much, he must be with her. Your H's friend sounds as sneaky as Alma Warren, the woman that my husband has been lying with. She has him convinced that she is his best friend. In my book, best friends would encourage the person to do what is right; put the marriage back on track. Friends do NOT, under any circumstance, come between husband and wife. Your h's so called friend, knows what she is doing, and is playing you for a fool.
Please, do not allow your husband or his so-called friend to do this to you. It is not only degrading, but humiliating.