frustrations T_T

So I've been continuing practicing "From the Beginning until now" but one of the major problems that I'm facing is that there are certain sections in the piece that I can play really well and would be quite confident of playing in front of the camera- but then there are the other sections (especially towards the end of the piece) that are...to say the least: simply shaky. I think it may be perhaps the way I practice that caused this to develop? - Sometimes I try to practice the piece by playing as far as I can without making any mistakes, but then turning back and starting over as soon as I do make a mistake -this method does help me practice the beginning (probably contributes to my fluidity b/c I keep having to repeat it over and over again lol) but it doesn't do much to help me work on my shaky ending (I never make it far enough in the piece before I mess up! T_T)