I spent a year on a high planning out my business. I ended up being very successful at it too. Won awards even (it was a service type business with a little retail). But in retrospect it was most definitely part of a cycle. I was so high on the details. It consumed me. Once the business was a success, I wasn't interested anymore and began a cycle set out to destroy it little by little (overspent on merchandise, closed shop early for no reason etc). I don't deal well with success and do everything I can to self-defeat without realizing what I'm doing until I've already defeated myself.

My advice is to take it slow and don't get caught up in the high of it.