I wouldn't say, "if you aren't hungry, then there's no point in eating," because when it comes to eating disorders and being underweight, there comes a point where you don't get hungry anymore. Sometimes you do need to eat more to stay healthy.
It sounds to me like you may have an eating disorder. Things can get really, really bad and it will ruin your life. Mentally and physically. I think it's important to have a healthy relationship with food and to be okay with being a healthy normal weight. Because a healthy weight is not fat. And healthy is beautiful.
Now is your time to get help. Get help now before it's too late. You are really young right now, so it's hbetter to get this under control before it takes over your entire life. You can see te warning signs now, so it's time to go. It might be really scary and you might feel like, "oh no, I am okay!" But this is just a defense mechanism, it's your eating disorders way of trying to control you, much like an addiction, but it's better to ask someone and ask them to help you, just to make sure. It will be worth it in the end, and you have a higher chance of beating this if you get it taken care of sooner, instead of 5 years down the road.