I'm empathising with you so much right now. Can we have a cry together? When I was reading your posting, I thought I was reading something from my own mind.... I'm in a dark place right now too. This is so hard. I never thought it could get this bad.
I also feel incredibly alone. Like you said, no one understands. Family and friends can't even begin to understand what living with this is like. I have overwhelming sadness too. Anxiety and depression are here as well.
Please know that you're not alone in how you feel. I don't have children, but what's interesting is that my cat picks up on my sadness. She gets quite upset when I cry. Your baby looking at you made you cry harder.... My cat looking at me makes me cry harder.... I'm not sure if I should laugh at what I just wrote or not.... LOL. Okay, I'll have a chuckle at my own expense. I've become "the crazy cat lady".
Do you feel hopeless? Like this is never going to get better? I feel that way a lot. I reach out to God in these times. I know I'm going through this for reason bigger than I can understand. But that doesn't make me feel any better.
I hope and pray you have a restful night. If you ever want to talk, I'm around.