Help! Is my cat dying is there anything I can do??

[pagan9000]

My 17+ cat has had arthritis for many years she cannot move very easily anymore and needs a ramp to go up and down stairs & cant step in and out out of catbox(she would back up to it to try and go so we switched to something she didnt have to climb in and out of). I believe she also has been going blind (black part of her eyes turned grey). lately she has not been doing to well she has stopped eating, and pooping. I was at my parents house today and she is vomiting even tho she isnt eating (sometimes dry heaving or water just coming up). My mom said the other day she was vomiting and voiding her bowels in the middle of the room she couldnt get up to go anywhere else, it takes her about 5 min+ just to cross the room. Well my question is are these signs she is dying we have been thinking so; If she really is what can we do for her (without taking her to a vet) I would like to but my mom wont, i know it sounds mean but she doesnt want to do that, any suggestions???