I had this last year. The problem for me was tightness in the calf and achilles (from racing on multiple consecutive weekends and not sufficient stretching) which manifested as pain in the plantar/heel.
I had 2 months off running, doing lots of stretches, calf dips etc, rolling tennis ball (better than golf) under the foot, raising legs when seated and rotating feet left to right and vice versa.
Orthotics will only mask the pain (i.e good for vital races but bad for cure). Having your heel raised will actually be detrimental as it puts extra pressure on achilles/calf.
It depends how quickly you can get back into shape/ are willing to cross train. You can run through PF but this can lead to much worse problems, some people suffer for years.
My advice is be careful, take a few weeks off running and just cross train (you have plenty of time before manc 10k and esp. GNR), get a good physio and stretch lots.