Why is it so hard for me to grow up?

okay im 17 years old and a senir in high school this year.And im havin a hard time growin up, the otherday i was arguin with my mama about this and cryin a lot. I dont know what it is holdin me back, im kinda quiet and soemtimes shy. I havent started dating or driving and the one job i had i quit because of my shyness i had a hard time working with my co-workers and opening up to them. I just want to become more mature and independent