Sticky situation - please help?

To be honest, if you are not truly happy in the current relationship you are in then I would break up with him. The difference between your backgrounds is obviously a big issue and you should only go at a pace that you are happy with. Regarding the other guy you like, I would go for it. You never know until you try, so be bold and see if he likes you back :). You both have a lot more in common and you have the chance to get to know him gradually at a good pace. Good luck. Xx