blob,achilles probs could also be referred pain.Rather than just treat the symptoms you need to hunt for the causal factors.
eg - Tib Posterior is known to refer to the achilles area as does Soleus.
Before doing lots of arguably not very effective stretches [compared to various muscle energy techniques] have you had Tigger Point therapy release in these areas?
Has your pelvic alignment been checked?
Leg length discrepancy?
What was your warm up/cool down protocol when you were running? ie few mins warm up on the indoor trainer,dynamic mobilisations replicating the running action,self massage,PIR type stretches on high load muscles or areas of potential injury...etc.Takes me at least half an hour to get ready for a run,which can be a pain in the a,but it reduces the risk of injury,lowers perceived exertion,promotes a smoother running gait,and despite advancing years enables me to continually set PBs despite very low run mileage.
What sort of manipulation to the tendon have you had?
On a pedantic level,you'll be suffering with an 'osis not an 'itis.
Rather than wanting an answer per se,just give my brief pointers some thought.If these factors haven't been looked at [they should have been] then find ye a decent soft tissue therapist.Not sure an osteo or physio is best for this,unless they have been trained in up to date soft tissue techniques.
Good luck.