Chronic pain and swelling in left ankle.

I've been suffering from chronic pain and swelling in the left ankle. The swelling was extreme between May and June 2017. The doctor who I sought treatment from, couldn't figure out what was causing such excessive swelling in the foot. He suspected a blockage in the lymph nodes but wasn't sure. I even tested for Filariasis, but to my relief, the result was negative. He prescribed a diuretic medicine for 10 days (Dytor 10 mg). The medicine helped, but only temporarily. It came back as soon as the course got over. The swelling went away with regular foot massage and chamomile tea consumption as suggested by my earlier physiotherapist. The swelling hasn't recurring since. But the pain keeps recurring intermittently and ranges between sharp pangs to dull aches. I also suffer from sciatica ever since I was diagnosed with acute lumbago in 2012.