RB - My Parkrun tour was with a view to getting fit for the STK10. It was actually an enjoyable interlude before marathon training starts again. I can't say I'm looking forward to the 12-16 week slog again.
I suppose the dilemma we all face once we feel we have 'peaked' is whether to train as before, or even a little harder, in order to maintain times, ease off a little and accept the reduced performances, enter different races e.g. more off road events or give up entirely.
J8 - Once you are fit again maybe try one long run and see if your mojo returns ?