I often find focusing on others' needs instead of focusing on my own misery puts that misery aside, at least for the time being. So perhaps remind yourself how you are being helpful to your aunt and grandmother during this time and allow yourself some measure of feeling good about that. Also, maybe acknowledge that this time of crisis is only a short period in time - it will pass and you will be OK. It's so nice you have your close friend for emotional support.
Hugs.