I totally get where your coming from, Im the youngest of both our families and he is 10 years older than me. Most of my friends are also 5+ years older So I have the same fear if we dont have any children of our own then Il be alone for the remainder of my life and probably end up in a care home with no visitors! Totally get where your coming from! He understands my fear and I think thats why hes willing to try fostering because even though they wont be ours via dna we hope they will still become our family. I dont speak with my own family but the one I made with people who support me helped him realise just because they arnt related doesnt mean they arnt family!
It doesnt help your fear but we ended up getting two cats and a dog who became our babies and I think that helped him get over "if its not mine its an issue"
I completely understand that lost issue especially when its drilled into us from a young age we should start a family. It is a serious issue and you dont want it to cause issues in the relationship esp having it on your mind when going for IVF is just going to add more stress you dont need.
I would sit down and ask him why is DNA such a huge deal, You could get adoption from birth so the baby would be yours from its first day. (And men dont bond with babies until they are born!)
During our fostering process its really opened up my OHs eyes to just because it itsnt mine doesnt mean it doesnt deserve a loving home that I can provide. Its something that can break good relationships.
Does he really 100% want children? If so ask what the difference if its from Ivf or adoption, either way its a child who needs a loving supportive family to give them the best start in life.
I really hope the IVF works out for you.
But at the same time dont let his choice in life stop you from having what you want or affecting your mental health! Relationships are about compromise!
Sending hugs xx