infertility is ruining my marriage.

My husband and I have been married for a year (together for 5). He has 3 gorgeous boys from a previous relationship... and all we wanted was 1 more to complete our family. I have known from the age of 19 that I may need help with fertility. I have PCOS and endometriosis. A laparoscopy at the beginning of this year confirmed that both my tubes are completely blocked and our only option is <a href="https://glowing.com/glow-fertility-program">ivf</a>.
Recently we have been really struggling, at all our appointments my husband won't have an opinion, all he says is he will do whatever makes me happy.. I've told him this makes me feel like he's doing all this for me and that I want to feel like this is what he wants too.
Whenever I get upset he tells me everything will be ok and that if we can't have a child of our own then it won't be the end of the world. I've told him for me it would be devastating.. I adore his boys I really do.. I treat them as my own and he always tells me I'm an amazing stepmom, but for me it's just not quite enough.. I'm not their mum, I didn't give birth to them.. I didnt see their first steps, words, take them for their first day at school. I feel like he doesn't see things from my perspective. 
It's starting to effect our marriage, I feel alone so I keep my struggles to myself.. I find myself resenting him for not being there for me.. if I ever try to talk to him he says we're in this together but I don't feel like we are.. He doesn't know how it feels to face the idea of never having a child of your own and he won't try.. he just says we have the boys so everything will be ok. 
Am I being unreasonable? How can I stop this destroying our marriage? 
Anyone been through something similar?
Really appreciate everyone's view point.