What Causes Daily Headaches, Head Being Off Balance And Double Vision?

Hi, im 16 years,old I,get daily headaches they start in the after noon and are genarly around the top left of my,head my balance seems to be off and I only get double vision when im reading words my left ear pops when I yawn could it be a ear prolem, may be I kneed glasses I keep think and am worried its a brain tumour I hada mri and like4 ct scans of head in december what,could,it be,it,would be well appreciated if,anyone could help thanks mike