ttc but scared..

i am 38 yrs old and my husband is 23 he has 2 boys and I have one girl. he wants another girl so bad.. so to the point I miscarried about a month ago but of course he is ready to try again like crazy. To be honest our sex life is quite frequently but I'm scared that I can't give him what we both want not only cuz of my age but because I already miscarried, the strange thing is that I didn't think I could even get pregers again in the first place so once I found out I was quite astonished.. any thoughts about my situation? like should I just breathe and let things happen and quit worrying?? I just need some kind of input I'm anxious as hell!!