Richie,
Your requirements to regain your SEP rating are 'training as requried' followed by an LPC/Skills test with an examiner. Depending upon how you feel, this could be anywhere from none (not recommended!) to lots (unlikely!).
As for the night rating, there is no stipulation in the rules to say that the five hours have to be post licence issue. Therefore, if you wanted to, you could complete your night rating (apart from the solo bits) whilst 're-training'.
Personally, I'd concentrate on getting back in the saddle in daytime VFR and build up experience/confidence before taking on the night rating. One step at a time.
HTH