What Causes Severe Pain On Top Of Left Foot And Ankle?

three (3) days ago I started having bad pain on the top of my left foot. (This is not to uncommom for me as I have had foot pain and foot problems a some time). Then the pain got real bad around my ankle area. Now it seems to have gone a little higher, above the ankle. It feels like Bone pain. It is hard to walk on it. I also have kind of a sick feeling in my stomack, probabl due to pain?I am a high risk for stroke (fathers side). I was on blood thinners until a year ago when I had a bleed. They took me off of the thinners and put me on baby aspirin. I was wondering if it is possible I have a blood clot? Also, I have had AFib for years. I am a 80 yr old white male and active but I do take a number of meds.Your opinion please??