I'm Concerned About An Aching Pain In My Left Foot,

I'm concerned about an aching pain in my left foot, lower leg, and knee, which I think might originate in my foot. My left foot is also colder than the right. I just saw a foot doctor who says there is fluid around the joints in my foot/ankle and diagnosed tendonitis. What scares me is the difference in temperature between my two feet. I'm concerned about a circulation or nerve problem, but my foot doctor didn't seem that concerned since while in the office, the temps measured on both feet were the same. She prescribed nsaids, a topical gel, and wants me to come back in 2 weeks. I'm wondering if I should get another opinion. Does this sound like something that needs immediate medical attention?