Scared to cross U.S border.

Hey guys I have a few questions about crossing the border..
last year I stayed in the states for almost 6 months I usually go to the states every summer but not for that long.

Anyways, I want to go back again this summer and stay for maybe about 3 months I am very scared to get denied cause of me staying in the u.s for 6 months.

I read on here that I have to show some sort of ties back in Canada.. I live with my parents and Im planning to quit my job before I go there because when I come back I want to go to school full time. I have my car insurance that I pay for monthly, as well as cell phone bill and thats it! I did save up a quite a bit of money so I could provide for myself when I am over there. Could I get denied cause I have not provided enough proof that I am going back to Canada (which I am) How can I show them that I dont plan on staying there illegaly? Will it be easier to fly or go by car?

Don't be scared! US is great!