Losing My Best Friend: Coping with the Death of My Dog

Hi! My life has completely turned upside down the past week. I found out my family’s dog of 8 years old had liver cancer and it was too late to help her. I had the responsibility of watching her all day yesterday and it was the longest, hardest day to see her so uncomfortable and sad. Once my sister came home we noticed she was drooling a lot and figured she was sleeping. I told her she could run to cvs and figured our dog would be fine for 20 minutes. After she left I heard my dog gasping for air and all the suddenly everything went still and I freaked out trying to save her. She unfortunately passed away right in front of me and soon after my mom and sister came and gave her comfort. I have never felt so fucking helpless and sad. That sound she made and the whole situation kept me up all night and knowing I had to bring her to the vet to get cremated was the hardest thing to do. I’ve been crying nonstop since last night. My anxiety levels are rising and I’m hurting so badly. Can anyone help guide me with some support and how I’m able to move past it?