I agree with a lot of what Annabel says and wanted to add that you could have a look at the tags in the search engine to read about other triads that have come along here. Try a tag search for "triads."
It sounds to me like your triad is more about the sex than anything else, although that could be because that is all you have written about. I think that just letting the sex go and creating a vee might help. Find yourself a woman that clicks and let your hubby get on with it and be the hinge to your vee. There is nothing that says this HAS to be this configuration it sounds like you could be close loving friends that share the same man. Start making time separately in the form of date nights that are separate and get yourself out there again before you REALLY feel left out by this obvious (to me) lack of connection. Or worse, before she starts pushing to be something she isn't.
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