It appears to me that your husband isn't really adhering to the ethos of polyamory, which is about LOVING multiple persons simultaniously. From what you have said I get the picture that he has withdrawn love from you rather than added love by embracing another. You seem to feel abandoned, and it looks as if you have been to some high degree.
There seems to be a breakdown in communication, or perhaps the needed communication skills and attitudes weren't present enough to begin with. In any case, it looks to me that your relationship with your husband is in crisis and that couple counceling may be needed unless the two of you can jumpstart a much higher level of loving and intimate communication which respects the needs each of you have--and you especially, since it seems to me that your husband has forgotten about your needs.