Weight Watchers has a really sensible, healthy lifestyle approach to losing weight, and I think it would be suitable for a teenager. It's probably one of the most painless ways to lose weight, and they give you a lot of support and help. They use a point system, which is much easier to follow than a strict diet, and it doesn't really eliminate any foods, although you do have to watch portion sizes with certain foods.
If you don't want to go to WW's meetings, you can follow their plan on line.
You can follow their plan at your own pace and you are given such a wide range of choices that you don't ever have to feel restricted, and you never have to go hungry. And they give you lots of useful tools and tips to help you along. Check out their Web site, or go to a WW's meeting and see what they are about. Some of the WW meeting locations also have drop-in hours, so you can just visit and chat with a staff member (like maybe during those times you are home alone bored).
since I'm alone i feel like i could eat whatever i want like nobody could stop me
That sounds like eating whatever you want, when you are alone, is one way you're asserting your independence because, "nobody could stop me". The trouble is, asserting your independence and "freedom" that way is really self-defeating, because you don't like being overweight, and it's not true "freedom" because you're allowing yourself to be controlled by all that tempting food. You need to put yourself back in control, and you need to start making choices that will get you to the goals you choose and want. And wanting to be healthy, and to feel healthy, and to look healthy, is a great goal!
If you are home alone and often bored you do need to find some interesting things to do with your time. Why are you stuck at home? Are there any after-school activities that interest you? How about trying to learn something new or developing a new hobby? What sort of things do you enjoy? Do you like reading? Listening to music? Spending time on the computer? Do you have friends you can spend time with?
Maybe you need to set some goals or work out a plan to help you deal with boredom.
I think there are a lot of folks here at A2K who can give you useful advice, jaidaA. Just let us know exactly what sort of help you need.