Hi! Welcome to the forum. This is definitely a good place to be when you are dealing with all the issues a chronic disease causes and feel that those around you can't relate. Crohn's is a really tough disease to deal with at any age but especially so when you are so young. This isn't how you expected your life to be and your life probably feels very different to the lives of your friends and other people your age. It's very understandable that you would have all kind of emotions about that. There are other people your age on this forum dealing with Crohn's and it may help to read about their experiences and talk to them so that you know that you are not the only teenager dealing with this. But so many of us here, regardless of age, have had similar feelings. You are not alone in this and the forum is a great place to find support.
How have your Crohn's symptoms been since diagnosis? Do you have anyone IRL that you can talk to about these issues? It's a good thing that you have recognized these feelings and your need to find other people to talk them through with. Hopefully this is the first step to make you feel more like your old self. I think we often find that we can't feel exactly like the person that we used to be because life experiences change us and we adapt and evolve but that doesn't mean we can't be happy or content or connect to those around us. Keep talking. I know there are lots of people here who will identify with your feelings and experiences.