I have the same ankle tendonitis. I got it a couple years ago from increasing my running distance too quickly. (Tough way to learn that lesson.)
I went through lots of anti-inflammatory drugs, icing, 1 cortisone shot, and lots of rest. I found that a good set of orthotics made the biggest difference. I have a custom made set that honestly isn't as good as a brand called "Sole". You heat them up in the oven and they conform to your foot. You have to take out the original insole in your sneakers to get them to fit. I also wear an ankle brace when I play. (McDavid or ASO are the best in my opinion...the type that laces up and have the figure 8 straps.)
Now I play 3 times a week for ~1.5 hours at a time and have no problem. Every once in a while it acts up a bit and I just take an extra day off.
I think the best thing was the insoles to give some support to your arch. The brace definitely is good, but I can play without it. At this point it is just a psychological thing.
Good luck. Be smart about it and give it some rest before you play a lot.