A former Canadian figure skater turned podiatrist recommended a simple cure that worked for me (bothered only on run). Anti inflammatory topical gel (diclofenac) to ease the pain (took a few days as I remember correctly) And once subsided, used a foam pad cut out (custom) to the shape of my heel where I had an indentation just below the prominent bony part of heel. Go to drug store and either find small foam pad or double or triple up moleskins and apply to your heel. (3 inches long, several mms wide and deep)If it works like mine did, then just attach To inside of shoe heelsjust adjacent to sole inserts. That way you don't have to apply to your heel evertime, but will be a shoe insert of sorts.

Basically it kept my the lowest part of heel from pressing sharply against the heel of shoe, calming the bone or bursa.

The minute I took off my shoe she said Haglund deformity, but did take quick X-ray. I loved tight shoes and skates in my youth...led to Haglund and Morton's neuroma. Wider toe box helped Morton's, no surgery and this simple solution from former skater has worked great for last 3 years or so. Lucky I got her for treatment, she had first hand knowledge.

Found this helpful. http://www.heelandarchpainclinic.com.au/haglunds_syndrome.html

Good luck. Hope it made sense.