Afraid? Scared? Shy? (Ashamed of your hair?) Or did you get a Summer Quest challenge that tells you to read a book about feelings?
You can find some very good books by searching through the 150s, the Dewey section for psychology. And of course many, perhaps most, of the chapter books are not only about the characters' adventures but also about their feelings.
For kids, here is an excellent web site:
Dealing With Feelings
Adults and young adults: Try the books in Dewey 152 and the magazine Psychology Today. You may also find these psychology sites fun.