don't know if this helps or makes it worse, but...
I've been in a quad that is dissolving into I don't know what. It's been wonderful, hard, and ultimately not workable for 3 of the 4 of us, but all relationships have thier own lifespan. I am now wondering what the impact will be on my remaining lover relationship with my secondary, who does not define herself as poly but loves me still. I have learned that I probably can't find one relationship to meet my needs, that I can balance more that one relationship, that I can love more than one person at a time. I know that if my long term primary partner wants to move on, I will eventually want to bond with someone new who hopefully has similar qualities, and I wonder what this will do to my secondary relationship. My next real test is to remind her that I am poly, that I am not going to become mono now that my primary is leaving, and to ask her to stay. I look forward to the future when the pain is not so bad. I hope the same for you.