First and foremost - don't lose any sleep over it, no one is going to kick your door down at 5am and pull your toe nails out.
You've had the honesty to realise your error and hold your hands up, and you obviously didn't do it intentionally.
If the unit you were working didn't say anything at the time or contact you later that day, it's very unlikely that it will be taken any further.
Even if it does go further, the CAA take a very balanced attitude to such things, simply admit that it was a genuine error and that you have learnt from the experience, they may recommend a check ride with an instructor on a similar or same route, but they won't tear your hard earned licence up.
