Loss is hard

I'm 38 and my husband is 42. We have 2 kids, age 18 and 14. I have had 3 miscarriages, the last being in Sept. I found out I was pregnant in Aug, being a total surprise. I had been on extended cycle birth control pills. I missed my period so I took a pregnancy test before staring my new birth control pack. It was positive. I was shocked. I thought we were done having kids. No sooner than I found out I was pregnant, I miscarried. My water broke and I started hemorrhaging at 16 weeks. But my baby's heart beat was strong for a few more days. I had my baby a few days later. He was fully formed and perfect. Needless to say, I'm now so confused. I always wanted another baby after my youngest but I had a miscarriage at 11 weeks when she was about 6 years old and decided that I couldn't go through that again. Then it happened again anyway. I know I'm getting older and the thought of never having another baby terrifies me. But so does another miscarriage. It's also a little scary starting all over with an adult child. People will think I'm crazy. I have not used any birth control since my miscarriage and we've decided we will not start any right now. Just see what happens. I have PCOS and recently lost 100 pounds and am finally having regular periods. Any advice? How long does it usually take to get pregnant in your late 30s? Am I crazy for wanting to start over?