Ugh! I'm 4 months postpartum and my hair has been falling out for about 8 weeks. It's such a pain and it feels like it will never end!
With my first son, I lost hair until he was a year. I felt like I should be wearing a hat all the time. My husband assured me it was only noticeable to me but it still makes me feel conspicuous.
I echo the advice of the other moms to go see your doctor about it. It's probably just taking longer because of hormones but it's nice to know if something else is at play. In the case of my first pregnancy, it started changing back to "normal" after a year.
Find a good hair stylist and ask them to help you choose a style that helps hide your thinner areas. Good luck!