I always like the advice line, "Don't look back and regret what you did, regret what you didn't do". IOT- what have you got to lose? Many of the anxieties you've expressed may either be allayed or cemented in that year and, in my view, whatever you'd decide to do at the end of it, you'd be the better man for it.
Don't be the, "I could have been a fighter pilot, but I couldn't be arsed" bloke in the bar!
CG