For one thing, in the sequence

ADCON0.6 = 0
ADCON0.7 = 1
CM1CON0.3 = 0
ADCON0 = %00000001 'Set AN0 active


You first set ADCON0 bit 7 and then clear it two instructions later.

Try

CM1CON0.3 = 0
ADCON0 = %10000001

Instead