So I ordered myself an arch support as my ortho suggested. I finally got to use it early this evening. After a 1.5-hour walk-and-run combo I could still step with my right foot without wincing.
I was ecstatic. I was cured albeit in an artificial way. A workaround. But who cares? I can finally get rid of those expensive painkillers. And start visiting takbo.ph for that first official marathon.