Most likely you have MTSS (medial tibial stress syndrome).
It may be associated with bunions given the length of time suffered.
NOTE: although unlikely due to having it on both side gout is on increase because of fad of high protein diets (should be investigated).
This comes from flat arches. the pain is often relieved during walking but inhibits running.
The pain will feel achy at rest and may even throb after long walks. It should run from the back of the inside arch towards the bump on ankle the radaite into the shin.
Foot wear is the biggest issue. stop wearing heels and don't wear flip flops or shoes made from fabric. walking boots are best but with summer and heat often not a likable option for women. if this is the case a good ankle strap and orthotic solution will create stability.
Ankle strap will provide the quickest relief.
ICE twice a day for two weeks especially directly after long walks.
Ultrasound and ESWT are very effective.
Regards,
Niall Marshall-Manifold
London Foot Pain Clinic