How to accept that you are done having children

So a bit of a backstory. We currently have a 11 year old daughter. It took us 2.5 years to conceive with her. I have had 3 miscarriages since that pregnancy. I just recently had gastric bypass surgery and have lost over 50kg.

I am having a very big desire to add to my family but the problem is that my husband is absolutely against it. He thinks the age difference between our 2 kids would be to much. He also believes he is to old at 38 years old. His father was an old dad and because of that didn’t really play with his kids. I have explained to him how he is a different person to his father.

I having troubles just accepting that we will be done at one child. What also doesn’t help is our daughter cries because she doesn’t have siblings like everyone else. She so badly wants to be a big sister. She feels that once we are gone she will be the only one around and lonely. She doesn’t have cousins to fill that void either. Any advice would be great.