This is Dr. David
have you had your legs checked for DVT with an ultrasound scan?
if you have had strokes before and afib, you are at risks for blood clots in your legs which can cause swelling
if you have a weak heart, you can have congestive heart failure and swelling and edema in your legs
this would require a diuretic like lasix or help you get rid of the fluid by increasing your urine output.
also if you have low blood albumin levels, this can cause more weeping edema in your legs as the albumin is not there in the blood vessels to help keep the fluid in the blood vessels.
are you elevating your legs at night above your heart to help decrease the swelling.
you should go to the A&E right away and get leg ultrasounds to check for DVT blood clots in your leg right away
have you had this checked?