That's interesting. A couple potential problems that would need to be workshopped include the fact that usually your arm will be trapped under your opponent's arm rather than over his shoulder, and also if you don't manage to turn onto your side then you're pulling him into you and increasing the pressure. That being said, locking yourself to your opponent, moving your hips towards him, bridging him up over your head and then rolling to the top is the classic escape for this terrible position, and it looks like you're very much on the same track!