Thanks! Will try it out later. I got the old engine which I created from the tutorial and edited some codes. It works as I want now 
I skimmed through your program and it seems like it does what I did in mine.
Regarding the results I got with my old engine, it shakes very little (almost unnoticable) and its z remains (-1<x<1). I used 1 and -1 as a margin of error which is barely noticable, especially when I zoom it out further (much further). I must thank you @wezrule, for helping me out and showing me my mistakes. Once again thanks a lot and good day.