I am so sorry for your loss! I will pray for you and your baby.
I had a miscarriage at 5 months and it was very, very sad. I understand the grief you are experiencing. I know it is very difficult to understand right now, but God is Good and He has a plan for you.
I don’t know of any online support groups, however, maybe some other women will post replies on this forum that will be helpful to you.
God Bless You and Your Family,