Why won't these painful shin splints go away?

I recently attempted to return to running after a 4 year sabbatical following the birth of my first son. I started slow and followed all my old training when getting back in the swing of it. I knew I had gained about 30 pounds and after having past issues with shin splints because of not giving myself enough time to adjust (I push myself way too hard and have gotten all sorts of injuries from it) I made sure I took it easy. But about only five little piddly walk/jogs in, I got that bad pain in my shins. I went down to only walking, eventually stopping altogether. I took about a month off and purchased some special shoes (I like to go barefoot) to wear around the house. I then took up biking as alternative exercise & lost most of the weight but for the last 3 months I've tried to go back to running and even a few fast walks with the dog has my shins aching, and even if they don't hurt when I walk they are so tender and sore; my three year old ran into me the other day and I nearly collapsed in agony. Obviously I need to see a doctor and have made an appt, but I would like to hear from other athletes about this problem. I love biking now but I can go 12 miles and it still isn't the workout that running is and I would like to combine the two. I've never heard of shin splints staying around for so long...I researched that biking hasn't been known to aggravate shin splints and I do several stretching & strength building exercises....these suckers won't budge.