Grad school: when to go back?

[amberlyrose]

I have re-applied to my grad school program after taking a long break. I was just accepted back in and need to decide if I want to start in the fall or next spring. 
Part of me wants to jump back in right away, but I have a week long vacation planned at the end of September. I also have a similar vacation next February, but it's shorter. Fall is usually very busy for me at the beginning with the new fiscal year starting at work, the volunteer programs I'm involved with, both soccer and NFL being in full swing (I'm a huge sports fan). 
Spring starts out much slower for me, but I'm not sure that I want to put it off any longer. I only have 3 semesters to finish and I just want to get it done. 
I'm on a provisional status and must maintain all A's for the first semester. My last semester went terribly with my undiagnosed ADHD and an awful work schedule/boss. I know I can do it, but I'm also frightened. If I don't do well, then I get kicked out of one of the best MPA programs in the nation. 

Any suggestions? A kick in the ass?