Suggest Remedy For The Tenderness Of Achilles

I think I hyperextended my achilles on a machine at the gym....the 'standing calf' machine....didn't notice until after some basketball but it was quite tender for three days. A week later I had forgotten about it and lightly jogged through the rain. Boom, tnder again. Now three weeks later i have an occasional feeling of heat in the tendon. Strain? treatment? recovery time? I am an advid mountain backpacker next trip 126 miles in Sept. Advice?