Glad to hear its not a stress fracture. Not that Plantar Fasciitis is an easy way out! You might try gel heel inserts (in all footware not just tha bike shoes) and calf and foot stretches definitely help. The natural history is that after 2 years almost all sufferers have recovered. Thanks! If you cannot wait:

Re surgery: Do not let anyone talk you into having the fascia divided at the heel insertion "to heal up again in a longer position" it will bugger up how your foot works and will be painful (and is archaic). A relatively painless opertion is Posterior tibial nerve release just behind the ankle bone - I have seen it work on most people and they can still walk/run normally after it.

Good luck. It must be so hard to not be able to do the activities you love. I really sympathise.