Laying in bed

There I was this morning, sound asleep when suddenly I woke for no apparent reason, then I layed there and you know how your mind starts to wander. I'm in the middle of reading Eckhart Tolle's - The Power of Now and i know now that I seem to pay more attention to what my mind is actually saying.
So then, I turn over, thrash about in the sheets, saying to myself "go to sleep" but to no avail. Our 18 year old cat, god love her, started her morning coughing routine - so I thought, ok, I'll just go to the loo and then I'll get back in bed and I'll go back to sleep. So that's what I did, both of the cats for once in their lives looked tired, and at me "what on earth are you doing up at 4.43" then of course as the toilet is right near the cats bowls, as soon as I walk that way they run to their bowls and therein lies the problem.
So I got back in bed, but both cats now were at the door, i got back in bed, thrashed around a bit more telling myself to go back to sleep when I thought "this is clearly not working, I'll get up"
Tiger, the 18 year old cat has almost stopped eating now and she is going through the same process as Blue our 15 year old cat did. I hate to admit it, but I think she's heading out soon.
So, if anyone can offer any tips on what to feed her, I'd sure appreciate them. I've tried tuna, ham, hills science diet which she actually ate a bit of today, going to try her on some mince i think and see how she goes. She's gotten so thin, and the vet just tells us that she's an old cat - hey, I wish I could live to the ripe old age of 19 cat years thats for sure but I don't want her to suffer in anyway.
D told her before he left for work that she had to still be here when he got back in 3 weeks, she looked at him like "where am I going?" I'll just keep plodding along with her, and feeding her a bit here and there when she wants to eat, that's all I can do.