“This sounds exactly like plantar fasciitis, despite a lack of arch pain” says Colin Papworth, “and you might need to look at a prolonged period of recovery.”
It's essential that you decrease your running time drastically or even stop running altogether to give your body time to heal the damage you are doing – this really is the key to recovery.
Stretch and massage on the calf muscles and plantar structures should reduce the tension on the tissues.
Increasing the amount of support you give your feet – either through orthoses or shoes – can help, as long as you make sure it’s the right support for you.
If you do have to run, ice for 5-8min at a time and repeat 3-4 times after running.
If you've been trying to run through the pain of plantar fasciitis for several months then you might have to consider a longer period of reduced running. Frustrating now, but safer long term.