Oh, I'm so so sorry for your loss.
Sweety, you feel like you've lost a child because you have lost a child. You deserve time to grieve, the opportunity to talk about him, about your plans for him and for your family. Please don't feel like you can't share those very important things and need to be brave and strong. Just by getting through what you have already your bravery and strength are beyond my understanding...
I'm so pleased that you are able to recognise the gift Freddy was to you and your DH. How special for you both to have that to hold on to.
I really hope you find the support you need on here, and in your family.
Take care of you.