You can write on here what is bothering you specifically. There are many people who can empathize with you. They either have similar feelings or experiences. Also if they know what you are dealing with they may have helpful suggestions. My daughter is 11 and I suspect she may have some ADHD tendencies as I have noted them in myself and my family tree. She retreats to her room at times as well and gets creative. I know she's in there making a mess but it calms her down. It's an outlet. So, now that your getting older, finding new ways to vent, communicate your feelings is important. It's hard to slow down sometimes for ADHD people. Maybe use a notebook and write out how you feel. See it from another perspective?
Today, I was feeling especially negative. So, I drew a picture of an ugly monster. I imagined he was the "negative thought monster " The one I kept telling to leave. So, to make it offical, I drew a big circle around him and crossed him out then took a darker color so I couldn't see him at all and scribbled him out. Sounds silly? But it made me smile, laugh and really I can't even think of why I was so bummed out before.