The van is almost at the give way lines before you even turn left onto the same road as he is on.
He had no way of knowing you were intending to turn across in front of him at that point.
At what point did you indicate for a right turn with your arm?
If you indicated your right turn after you joined the road he was on, he did not have time to stop before the give way lines.
If you indicated your right turn before you joined the road he was on, how would he have known your intention to cut across onto the cycle path?
Perhaps you should have moderated your speed a bit and everything would have worked out just fine.