Yes – your legs aren’t up to the task at this point in time.
I predict that this thread will bring up the following responses:
Go barefoot – that’s a daft idea as you’ll get loads of injuries before you see any potential gains,
Adopt a forefoot running style – that’s a daft idea as you’ll get loads of injuries before you see any potential gains.
My tip would be to look up eccentric exercises for the calve muscles or Alfredson protocol and do them religiously. Maybe even get yourself a good deep tissue massage to set you off on the right path before you do so. Then once all is fine in lower leg land build up your training distances slowly and on different surfaces.
One other potential problem you might have is the camber on the roads or pavements that you run on. Find somewhere flat to run – maybe the grass banking round a local running track.
Edit: told you so.