warning came up on the dash bored saying low oil pressure stop engine
so I came of the motorway and found a place to stop
started it back up same warning light I had to drive it for 5 mins
I'm afraid mate, 'STOP ENGINE' means just that, it's not a 'when you can' request, it's an immediate order. If you don't turn the key off straight away, it'll probably have buggered it.
Sounds like you did far too much driving with no oil pressure.
I'd be preparing for the worst.