I should add, in an effort to answer Harmony's original question: no, if you stop taking it, in my experience, there is no 'withdrawal,' at least, not in the traditional sense.
If, after months of taking creatine, you are eating enough lean protein (say, 1 gram per lb of bodyweight), and you are hitting the weights hard (and staying away from processed sugars), I suspect you will only continue to see gains.
That all said, I would humbly suggest you not do any of those things. NO ONE should just jump into heavy weights (not that you are, but just in general). Again, if you are currently working your way through a balanced exercise regiment and maintaining a strict diet (diet is 95% of any successful exercise gains), then supplements are really just not necessary.
Trust me, I've spent more than I care to admit over the years on jugs and jars of all sorts of things, and at the end of the day, nothing has worked better than simple clean eating and lots of sweat.
For the record, I'm 42 and still workout an hour or so a day, six days a week (DON'T NEGLECT REST!)