What Causes Shortness Of Breath With Pain And Swelling In Leg And Foot?

Hi I am a 47 yro female, I have hypertension, asthma and type 2 diabetes. Over the last 4 days I am experiencing pressure in the center of my chest off and on. I am occasionally feeling short of breath. The pressure is not unbearable but just does not go away. The shortness of breath is different than an asthma flare up. Finally, I have painful swelling behind my left knee which is causing pain and swelling in my leg and foot. Lately both of my feet have been swelling but the left is noticeably worse.