Everythings falling apart?

well to start off my great grandma is in another coma and the doctors have no idea how much time she has left, we were not close but i always loved her and seen her when i could shes my step dads grandma so he's taking it pretty hard but to add to all the stress is our family dog is dying of cancer the vet said take a few days and come back hes in pain and nothing we can do. im not ready to let go of either of them. im 19 and we got the dog when i was 7 and hes my best friend. we did everything together.he was named after are favorite cartoon Scooby-Doo. so its will be hard to not see it on tv as i provide child care and its a favorite amoung the kids.. my moms having a had time to cuz it was her 1st dog on her own for her family and her birthday is this friday. i cant sleep at night and i sleep with him in the dinning room to take care of him and its making it hard to imanage him gone..how do i know things will be ok, how will i ever heal? im losing eveything i love at once and its hard to see my parents fall apart. im the oldest out of 3 kids and have feel i have to stay strong for the family but i cant..