how come your water retention so serious? your gynae know about it?
anyway, i used to soak my feet in hot/warm salt water. 1 pail of hot water (as hot as you can tahan), and 1 handful of salt. it helps to relieve water retention and muscle aches.
if possible, after soaking can ask husband/maid to help massage your feet. massage should be stroking motion upwards (like pushing the blood upwards).
can do e same for your hands if they r also feeling numb.