yeah 14 units is a lot. personally what I did was I picked up maths and english ext 1 both for a few weeks of year 11 to see which one suited me, then I dropped maths ext. and you could always drop business after a few weeks and pick up religion (I'm not sure if the rules surrounding picking up/dropping subjects have changed since then) if you found it too similar to eco. I'm sure what you picked is the right choice for you!! best of luck w your studies, don't stress about this too much, just try your hardest in whatever subjects you end up with. good luck w your studies