After doing my LLB (English law) can i go onto do the JD in America?

Have you actually started your LLB yet in England? Have you considered becoming "dual qualified"? Some countries give at least partial recognition to foreign legal qualifications. It is perfectly possible for a foreign lawyer to fast track qualification in England, and likewise English lawyers can do so abroad. British legal journals like Student Law Review are usually full of adverts like "qualify at the New York Bar". Maybe this could be of some help to you?