I said plantar fasciatis, too, because of the pain on waking, then I read the rest. But it could be that your ankle is injured, which is causing you to compensate in your sleep (pointing your toes), which is causing that tendon to get all comfortable like that. Then when you stretch it out in the morning to walk, yowee. It doesn't cause swelling, though. The swelling means go to the doctor.

Hope it's nothing serious.

Karen