"She continues to refuse to allow me to be in any way close to another person male or female."
Um? Maybe I'm taking this more literally than you meant it, but this sounds borderline emotionally abusive to me, all poly stuff aside.
If she won't work this through this with you without screaming and heaping guilt upon you (when you in every way respected her boundaries!), or if she truly is isolating you in the way you implied above, *definitely* go for couple's therapy. If she won't treat you with some basic respect and won't give therapy a try, ask yourself what the heck you're doing in this relationship.
The major players. Me, 30ish bi female. Gia, girlfriend of 4+ years. Clay, boyfriend/dom. Davis, ex/friend/"it's complicated." Eddie, roommate & fwb.
The supporting cast. Eric, Gia's husband. Bee, Gia and Eric's toddler. Dexter, Gia's lover. Helen, Eric's lover. Izzy and Nikki, Clay's partners. Liam, Eddie's husband.