15 month off ttc😢

My dh and I have been trying for about 15/16 months without any luck. I have been trying everything from vitamins, Robinson around ovulation time, checking cm and bbt. I'm one second from calling my doctor and getting a Full work up? What am I missing? Any advice would be over the moon. Our first was a wonderful surprise🙌, but with second it's taking everything out of us.😢