First of all, sorry for your loss.
I have had the same exact situation myself when my grandfather passed away and I was feeling the pressure to be strong but didn't feel like I could be and feeling suicidal. What I did was pray that I would feel okay enough to be helpful the next day every night. You can also watch something, sleep in, and/or have a treat, if that's what it will take to keep you going. I did some of those things as well. Good luck and know I definitely hear yu.