Possible infertility from chemo

How does someone at my age (21) cope with the fact I might not have anymore children? I have 2 boys. 5 and 2 years old.. my fiancé got Diagnosed with testicular cancer and had to get his Right testicle removed and go through chemotherapy last March through October. So our chances of having any more children are slim to absolutely none. All my life I’ve always wanted a big family and now that plan is ruined. I can’t imagine my life with only 2 children. It really Aggravates me when people mention “oh you’re so lucky because you have two already” yeah, I get that and I’m much more fortunate than others, but that still doesn’t make it hurt any less. I’ve been coping with it by lying to everyone and saying I’m fine with the 2 I’ve got because “my youngest is so bad and a baby wouldn’t be a good idea”. Which yeah, that’s true. For now. Every time I see a pregnancy announcement or my period starts, it just reminds me just how much I want another one. Has anyone been through this? How can I cope with this better? My heart is breaking and I have nobody to talk to. My fiancé won’t talk to me about it because he feels like I’m blaming him for it.