There was a song called No Turning Back by one of my favourite Aussie bands, The Sherbs, released in the US around 1981.
They were a bit of a cult favourite there at the time, so it may be the song you are thinking of. They also got airplay with I Have The Skill and We Ride Tonight.
Here are the lyrics, if it helps -
No, no
No Turning Back
I'm letting go
You know
I've tried to persuade you
But I couldn't make you stay
You wrote the story
And you let it end this way, yes you did
I'm short of the distance
I'm back where I started from
Preparing myself for the sound of the starting gun
You've had it your own way
You leave me no way out
And baby I'll never follow you down
To where you're going to
Now I can see we're through
No, no
No Turning Back
I want you to know my mind
(There'll be No Turning Back)
No, no
No Turning Back
I'm letting go this time
You know
I'm heading to windward
Setting my sails to the sun
Freedom is calling and I'll take my chance on the road
My journey is waiting
I've said all I've got to say
This is forever
Though I never knew that I could feel this way
I only want to say
No, no
No Turning Back
I want you to know my mind
(There'll be No Turning Back)
No, no
No Turning Back
I'm letting go this time
You know
(Chorus repeats, with variations)
The song has a strong keyboard presence all the way through, and also rocks a bit!