Sorry to hear about your rat dying. My rat is going through a tough time with old age (a little over 3 yrs now) but still keeps hanging on. I thought he'd go yesterday while I was holding him, but he's doing much better again this morning.
I can sympathize. I was thinking I'd get 2 more when he goes, but he's been hanging on for a few weeks now and it is so hard seeing him in this condition. I don't know if I can go through it again.
I hope you are ok, but this happens. Try to remember the fun you had with them!