There are several things you can do to help stave or delay the bordem and horrid thoughts of running. Daydreaming (just make sure to keep eye out for cars and potholes), take a cd player or mp3 player, use a treadmill and watch tv.
As for getting back into the groove.
I've never heard of Fartlek.
But depending on how many times your running a week, I would limit the amount of HIIT sessions you do. It is very taxing on your system, which is why it is so successful and recommended for fitness and fat loss. I'd say if your running 3x a week. only do HIIT 1x. if your doing 4-5x a week, I'd alternate and do it maybe 1-2x a week.
If your goal is to increase your 1.5mile time. I'd start out with doing 2MI at a comfortable pace that doesn't force to you pass out or slow down. And depending on how good you are at pushing yourself and your body, just go for timed 1.5MI run without slowing down. Or add a couple minutes to what you were doing before your injury and lack of exercise and calculate out your pace. Once you get to an acceptable time/pace every few weeks or so, try speeding up a few 10th's of a MPH for the entire run.
I do most of my running on a treadmill so its easier to see my speed/distance/time. Every couple weeks or so I try to up my speed a couple tenths for the last half or so of the run, and I also sprint out the last 1/8mile or so before I begin my cool down.
If the ankle is just a little sore, try riding it out, but make sure to give it good stretch before and after your run, and take good vitamins. If it becomes rather painful, stop, or at least slow down till it stops being so overwhelming. You will have to work through some tenderness/soreness, otherwise it will never be right, but you don't want to make it worse either.
Hope this gives you some ideas.
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