Spongy sole

Background: 68-year-old man, just retired. Months ago had some numbness in my right foot when I went to bed so, after much research, concluded I had Morton's Neuroma. Big toe is shorter than 2nd toe. So I've used the toe spreaders from time to time and nothing much changed. Immediately changed to all Dr. Scholls shoes and numbness comes and goes. Didn't see a Doc. Then looked at the possibility of being a bad walker and thought I might supinate while walking. So recently, on my daily walks, I concentrate on landing on the ball of my foot rather than the outside edge and lo and behold the numbness is not occurring any more.
Instead, the bottom of my foot feels spongy on hard surfaces, tile, bathtub, etc. and probably is from swelling. Feels like 4th metatarsal may be swollen. Am taking antioxidants but no specific anti-inflamatories. Any ideas?