With heels, as Kat said, definitely don't feel pressured into wearing them. If you do buy new ones, definitely go for something low, with a thicker heel, to prevent losing your balance. Wearing high heels that have tiny, thin sticks for heels takes practice for sure.
That said, my high heel revelation came when I realized that you don't have to walk differently - the idea is still to walk heel-toe, heel-toe. There will be a much smaller gap between placing your heel down and placing your toe down, but it is still, in essence, the same as walking in flats. Wear your heels around your home first. With no rush or worry about getting it right, hold onto something (or someone) and slowly walk heel-toe a couple times. You'll figure out just what angle to use, and then you can start walking alone.
It gets easier, I promise! I am far more in love with heels than I should be. I don't even wear them in public most of the time >_<