It sounds like you might either have plantar fasciitis or (more likely) achilles tendonitis. I’ve had to deal with PF for a good chunk of this year. The key is to stretch (esp. in the morning) and be patients. Don’t rush back into running. The worst thing you could do is reinjure yourself. Winter is a great time to take a break from running. It sounds like you’re doing to right thing by staying fit on the elliptical.

BTW, I came across your blog looking for Pfitz plans. Thanks!