Hi.
What you're going through and feeling is actually very common. You may be thinking about a lot of different issues now that weren't a part of your life when you were younger. Without someone to share your thoughts and feelings with, these things can seem overwhelming. Then again, you may be someone who is just more reserved about things than others.
But talking to someone should help you clear your head. Although you say you don't feel you can talk to your parents, maybe bring up a minor issue with them and see if the discussion goes well. Then you may feel better about talking about larger things.
Finding a counselor or a trained therapist might also help. They are trained to listen to you objectively and they might have insight that a friend or family member could be unable to give. Also, they have usually heard a lot of different stories, so you don't have to feel embarrassed or shy about talking to them.
To find someone, maybe ask one of the three people you do feel comfortable talking to, or a teacher or school advisor who seems caring. You can also look at the DEAL WITH IT! psychology resources.
Or you may find outlets on your own, such as writing in a journal, doing art, playing sports or doing something that you enjoy and that helps you feel better about yourself after you do it. That kind of stuff can also help you express yourself if you do decide to talk to your parents or a counselor, or it may help you better communicate how you are feeling if you share what you have created with someone else.
