Struggling to cope

Hi ladies
My partner and I lost our baby and it's coming up to the time where we can start tying again but it seems to be getting more difficult to deal with. 
I hurt emotionally more than I ever have, I'm losing sleep, and I miss our baby so much that it pains me. 
I am a wreck but I don't know how to deal with it. 
I also feel like I'm not respecting the baby we lost by trying again and feel like I'm pushing him aside and replacing him. I'm just really having a hard time with it all. 
My mum and grandma told me that it was probably my fault that I miscarried because I volunteered (have left now) at a cat shelter (the poo is harmful, but I knew about these risks and wasn't dealing with it, just feeding the cats) so I'm having to deal with that. My mum has apologised but my grandma hasn't so I'm very hurt by this too. 
There's so much going on but we desperately want a baby. 
Does anyone have any advice on dealing with the emotions and trying again? Did anyone feel the same?
Thank you in advance. Xxx