First off, kudos to you for starting well before your graduation. I think you can make your goal!
My brother lost 100 pounds in a year by walking every single day for an hour and eating less food. He didn't track calories, just ate less than he used to.
Calorie counting can be annoying and imo isn't necessary. I lost 40 pounds a few years ago, and for the vast majority of that I wasn't calorie counting.
What you could do to help plan your diet is honestly track every single thing you eat for about a week. Tracking will probably tempt you to eat less than you really do, but I encourage resisting that and doing what you'd normally do. This will be a bit tedious, but it'll really pay off. After you have your data, you can review it and see where you can make changes.
Working out 3 times a week unfortunately won't help too much on the weight loss front. I'd guess that with C25K, you're burning a net 200-350 calories each session. So, going with the high end, that means 1,050 extra calories burned a week. It takes a 3,500 calorie deficit to burn a pound of fat. So at that rate, you would theoretically burn a little over a pound a month.
It's more efficient to cut back calories. You don't have to count. Just see where your portions are too big, and which foods trigger you to have a bigger appetite (for me it's carbs) and minimize those.
Since the weather makes it hard to walk outside, how about a workout dvd in addition to your running? I recently bought 30 Day Shred for only $8 at Amazon. It's a very tough workout, but you could modify the moves and go at your own pace. Doing that on your days off from running will help give you a calorie deficit.
Good luck! I know you can do this.