Don't push yourself as hard as you can everyday.

You have to get yourself back into shape. I wouldn't do the 'count to 100' deal. Like, in about a month I'm going to start training for the Marines (I don't graduate high school until the May AFTER this one, and I'm not enlisting until August). . and I've talked to some trainers and people at the gym about what would be the most effective way to get it done and here's what the majority said;

You do it by time.

Start out by walking 30 minutes (I'm using 30 minutes for the explanation, but I'm going to do everything in my workout with more time, and if you've ran track before, you probably should too).
Then, the next day. . jog for 15 minutes, walk for 15.
A few days later. . run the whole 30 minutes.
Then, up the time. Make it 60.
Run for 30, walk for 30. Run for 45, walk for 15.

And keep doing that.

Distance running is pointless until you actually start training for the specific section of track you're going out for. Building up endurance is done by time. When you're running with time it's not about pushing yourself to your limits. . you should be running, jogging, or walking at speeds that you could do forever.

I hope I helped. .