I have the opposite problem, Im 5ft 7inch and I weigh in at only 68KG.

compered to the blokes I train with at the dojo (mostly british tradesmen or students) im shorter and lighter, the style taijutsu sint really bias towards any particular build, but you just have to adapt the style to suit your preferences.

I once fought a blackbelt TKD guy, he was very heavy and built like a grappler he had a wicked side kick on him. But he made sure he learnt the sweeps and grapples that are present (I beilieve) in TKD. They just arent considered the main feature of the style so to speak, but he learnt them because he wanted to use his build to his advantage within the style.

I think it seems youve made a wise move, youve got your 'heavy hits' but your also learning the fast and light stuff as well, once youve 'mastered it all' then you can use the techniques that work for you. Im no expert but in my opinion a good martial artist can adapt the style.