..its difficult to say...bc we dont know your weight and more titbits...see someone with expertise

Internal Medicine people usually don't have a clue. Go see a podiatrist IMMEDIATELY. I went to three doctors before anyone acknowledged that I have a problem. Good thing I was referred to a podiatrist. If you live in cali go to the Foot and Ankle institute in Santa Monica over on Wilshire. They are the BEST.

Maybe? TIBIALIS-POSTERIOR Tendinitis. VERY COMMON. It's the tendon that connects from your ankle to you knee on the inside.

does the swelling go down immediately after you stop running or does it take a while . . . how long?

wow i would consult a physician...that doesnt sound normal...my first instinct would be that u are over-exerting yourself..but this is speculation...i say see a doc. good luck