Help! sick dog

Help! Laika, my cocker spaniel has been our companion since she was born
10-1/2 years ago. For the past 3 days she had been panting a lot and 2
nights ago we had to take her to the emergency clinic in the middle of the
night because her stomach was hard and swollen like a basketball and she was
in great distress. They sedated her and inserted a tube down her throat to
empty her stomach. We took her to her vet yesterday morning but no reason
were given for her problem. Yesterday afternoon she was again swollen and I
rubbed her belly and she vomited a lot of dark liquid. She is not eating,
she is thirsty and she spends her time sleeping. Does anyone have any idea
of what I could do?
I do not want to "let her go" and give up prematurely and I do not want her
to suffer either. What to do for that dear old friend?
Thanks for your help.
Mireille