I was about to fall asleep and a call came in and woke me up. If you weren't yet asleep the call could not have woken you up.
Then, I tried to go back to sleep but failed. You could not try to go
back to sleep if you had not yet been asleep.
How to describe the situation above?
A call disrupted my sleep?? (Does it imply I had difficulty going back to sleep?)
I was about to fall asleep when a call came in. Then, no matter how hard I tried (and no matter how many sheep I counted), I just couldn't get off to sleep.
As a result of the call I was wide-awake.