I'm so sorry to hear about this roadblock, Phy. I have a good friend who's going through IVF right now. It's been a long, tough year for her, and her self-esteem and joy in life have taken a serious hit as she's been forced to ask herself if she will ever achieve her vision of being a mother. At the same time, it's really forced her to grow, and develop her ideas about who she is and what she wants in life, as she's had to think harder than ever about her future. I am certain that you will all take good care of each other during this time.
I'm sure this is an option that's crossed your mind, but I'll take a moment to give a shout-out to adoption. My sister is adopted, and she's never been anything less than my parents' child and my sibling. I don't know how being poly might complicate an attempt to adopt, and it's not always an easy road to begin with, but it *is* an alternative to consider.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.