I have had it so bad, I could barely walk. It took months of PT to fix.
Here were my instructions from PT:
1. Ice (like Ed said)
2. Stretches every day, and especially before getting out of bed or getting up after and extended time sitting. This really helps. Look up stretches for it, which are mostly for the Achilles
3. Until it is healed, NEVER EVER put any weight on it without being supported by your orthotic. I was told that if I got up in the night to pee, I needed my shoe on. In the shower, I had to stand on my good foot. Always wear the shoe/orthotic! I used green SuperFeet as many of the other OTC are crap.
4. Get the right shoes. If you grab the toe and heel and try to twist, they shouldn't. They also shouldn't bend in half.
5. Get another pair of SuperFeet for wading and other wet activities.
6. For some reason, many people can get by with Crocs. They violate all the known rules but they can help. I wish they existed when mine was really bad as I might have been able to wear them in the shower. I still have to wear SuperFeet in everything except Crocs and Keen sandals, which for some reason also work well for me. A friend swears by Biremstocks for her's (and she's not the least bit granola).
And last and MOST IMPORTANLY, wear a NIGHT BOOT!!!! As you sleep, your foot relaxs and all the micro-tears start to heal, but in the relaxed position. When you put weight on it in the morning, you re-tear everything that healed. The night boot keeps the foot/ankle bent at 90 degrees so the tears heal in the correct position. When you take it off every morning, be sure to do the stretches before putting weight on it (with your shoe on).
The night boot was the only thing that worked for me and helped me avoid surgery. When mine flares up, I wear one again and it is quickly healed. However, now I can get by with a light low profile OTC one. If you were to do nothing else but get the night boot, I think you will see some relief. You can get one from the Dr or order one online. I see them a lot at Goodwill too but obviously, you'd want to wash it well.
Good Luck!
(Here's what I wore but they have other types now