Maths A Level or Computing? I really need help!?

Ok so im not amazingly great at maths my mental arithmatic sucks however i can do the differentiation and the more complicated stuff ok. Now my old maths teacher from my sixth form college says i will never p and with him i never did. The college i applied to says im more than capable of ping what with the entry exam i sat and they feel i have a small amount of dyslexia. Now my concern is one college is offering me Maths but not physics, now i like physics a LOT. the other college is offering me Computing (programming) which i can already do. Now im not sure if i want to take a physics degree when im older or a computing course. What would you say is more versatile for me changing my mind at a later date?