Abnormal?

its not that i've been physically abused but when my friends touch me, like just normal girls and their way of like hugging and normal stuff, i get very scared. when i say friends, i mean girls. well guys too but thats a different story, i dont even like physical contact with people other than my family. and the only time i welcome it is when i am extremely down and i cant help but want to rely on someone. one of my best friends, a girl ofc, i kinda hurt her alot because im too afraid to be touched by someone. i dont think that its normal to be so afraid of someone touching or contact but i just cant help it. and i cant stand hurting her too and i want to hug her like best friends do but whenever i try to, i get incredibly scared and i start shaking. she tries to help me by poking me in the shoulder and telling me to relax but i just tense up and i cant think properly because i want her to get her hand off me. its like im repellent towards people and touch. i dont know what to do. any advice anybody? is there really something wrong with me?