2 years already

Lina
Hi this is my first post 
Me and my husband have been ttc for 2 years now 
We have 4 beautiful children 1 boy and 3 girls and we really want one more to add to the family but it's been such a hard road 😒😩 had a miscarriage and it was painful and we just don't get it how can this be normal to try for 2 years and fail and the doctors say it's totally normal anyone in this situation