Husband unsure about 2nd baby

I’m 37 and I’m struggling because my husband keeps going back and forth about whether or not he wants a second child. He has anxiety and is afraid it will get worse if we have another baby. My son is 4 and I’ve been wanting another baby for years. I thought my husband finally agreed to another, but then he started getting anxious again and I feel like he changed his mind. I don’t want to pressure him but I feel like we are running out of time due to my age. I’m trying to be patient but sometimes it just makes me so sad to think I may never have another baby. I remember wanting kids ever since I was a kid myself and I am grateful for my son but I want to give him a sibling so bad. Sometimes I just cry in desperation and frustration and I feel alone because I’ve never met anyone going through this. 😞