I'm scared to show my feelings to this guy?

He knows i really like him and he likes me too but i neva really show how much i care for him because Im afraid hes gonna take me for granted. I be wanna call him and tell him how i really feel but i think i would be self-conscious. How can i let this guy know i like him so much?? He thinks its too good to be true for a girl like me like a guy like him thats why i dont show my feelings for him. He's shy and he stares and flirts with me. His bestfriend knows i really like him. He havent been coming to school lately and i'm afraid to call him and show him i care for him by saying...."Where you at? Is you Okay? i'm worrying about you, come back to school!" Can yall help please!!