Scared to try

3 miscarriages back to back in a 13 month span. One was at 12 weeks, my heart is set on having another but my mind I keep saying no, I'm scared. I want to try again, I have a healthy 5 year old but would love to try for 1 more. The docs want to run tests, what should I expect, what should I do, and why me! Is all that runs through my head, everyone is announcing pregnancies and I'm here beating myself down. I feel as if I'm doing something wrong, am I not eating healthy enough, am I missing vitamins anything?! What is going on. :/ just so many thoughts and it just doesn't stop, and the one person whose been there with me just doesn't get it or understand (the husband) he says we'll try again but in reality IM Scared! Ugh idk :/