Try Mandy Ingber 's DVD Yogalosophy! It is an amazing workout but you are done in 30 min and see results immediately.
I also had the hardest time running until I downloaded the app Couch to 5K.
And stay patient! Oh...and throw away the scale!
First of all congratulations on deciding to change. That is a HUGE obstacle and overcoming shouldn't be overlooked. 25 pounds in 3 months is a very ambitious goal. I won't say you can't do it because that's really up to you. Setting goals is a great way to track progress and measure your achievements. Perhaps you might consider setting your weight goal separate from your time goal, or conversely set your 3 month goal and promise yourself that you're going to work your butt off during those three months to do the best you can. I have found from my own experience that when I combine weight and time goals I ususally end up discouraged and disappointed. Just a thought.
Since you're using MFP you can track your macronutrients (protein, fats, carbohydrates). To maximize fat loss, you want to decrease your carbs and increase your fats. I know it sounds counter-intuitive, but if you have your protein set correctly (at least 40%) then this will work for you.
If you're interested in losing weight, then it's simple: burn more calories than you consume. If you're not working your muscles then your body will break down muscle before fat. This will produce the desired effect of losing weight, but size and shape suffer.
If you're interested in losing fat, then you have to be MORE strict with your diet and you have to work hard on keeping your muscles while your body harvests energy from itself. This option takes longer, but the results are that you are stronger, leaner, and have less fat overall so you'll probably like the way you look more.
Both of these options produce weight loss. The first one will happen faster than the second but the overall results may not be what you're after. Both options require plenty of water as was mentioned before. DRINK LOTS OF WATER! As a rule I try not to drink any calories. Both options also require lots of hard work and consistency.