Hi Highschoolbabe! Welcome to the board! Cruisin is right - you came to the right place! You'll find lots of friends, inspiration, knowledge and motivation here!
The most important thing you need to keep in mind is that different things work for different people. You just need to be patient and take the time to find out what works for you, and if it's something you can stick to. But keep in mind that no matter what plan you choose, you WILL have bad days now & then - read the threads & you'll see that I'm having a TERRIBLE day today!

But I'm not going to let that take away what I've accomplished so far. Tomorrow is a new day.
I'm so sorry that you can't talk to your dad about this. I agree with Cruisin that maybe you should talk to your doctor and/or school counselor - he or she might have some great advice! But try not to dwell on the situation with your dad - try to be positive and think of things like the support you're going to get from people on this board. We're all rooting for you!
Anyway, here's what I'm doing to lose weight. Most days, it's very easy for me, but like I said we all have our bad days! I count calories during the week. It sounds like kind of a pain, but after a few days it's a really easy habit to get into, especially if you plan your meals for the day ahead of time. Monday thru Friday, I allow myself 1200 calories per day. I try to choose mostly healthy foods, but if I want something that's unhealthy, I still have it - as long as I make sure to count the calories. Weekends, I don't count them. I don't completely go nuts & binge (well, not usually!

), but I live it up just a little like maybe going out to breakfast or dinner. I also drink 64 oz of water each day. I keep track of all this by using Fitday (do a Yahoo search & you'll find it). It's a really great online tool for keeping track of your weight loss, food intake, exercise, etc. Check it out, lots of people here use it!
I also try to exercise 3-4 times per week for 30-60 minutes. Sometimes I just walk on my treadmill, other times I do videos. If you're not used to exercising & want a good place to start, you might try one or two of Leslie Sansone's "Walk Away the Pounds" videos. I have the 3 mile one (bought it cheap on Ebay!). It's a good workout, but seems so easy! It's about 40-45 minutes long. You'll be surprised at how even a light workout just few times a week will really help the pounds drop away!
So that's my weight loss plan. Doesn't cost a penney! It might or might not work for you, but it's something to consider, anyway. I've lost about 15 pounds since early May. That reminds me of something else I'd like to tell you - I've found that if I lose weight slowly (like 1-2 pounds per week), it's much easier to keep it off in the long run. I've always gained back the weight after crash diets. Besides, it's healthier to lose the weight more slowly, and it will give you skin a better chance to shrink back as you lose.
And you have to choose a plan that you can stick with for life. You can't just lose the weight then go back to your old habits, or it will all come back. That's why choosing something you find EASY is so important.
Sorry this is so long, but I hope it helps some. Stick around, we'll all be here cheering you on! You CAN do this!
------------------
"If there are no [mastiffs] in Heaven, then when I die I want to go where they went."
- Will Rogers