I think my dog is passing, im dealing alone with stress

Hello everyone

I feel… no words can describe My senior dog has been recently put on heart medication cause she had a terrifying episode, and after scans, some antibiotics meds too, for the first few days all seemed fine, then yesterday she wouldnt eat or drink, this morning she was puking bile, me and my mother took her to the vets both times, and things are just…bad, she seems weak, had to be given water in a syringe, still wont eat , i think its the antibiotics meds and its hurting me emotionally cause i feel responsible as i gave them to her,

About a week ago when she was shaking and we thought she was dyijng, My mother got super upset , so stressed out , and now she is doing it again, she takes it out on me, help please how to deal mentally.