Your charges won't be dropped just because you turn 18. Moreover, you can be picked up as a runaway and anyone who helps you can be charged with harboring a runaway. When you asked this question before you were advised to talk with your p.o. about your issues. I strongly suggest you do this as running away will not fix your problems but will likely compound them.
Juvenile court loses jurisdiction over you when you turn 18. But running away isn't going to fix it. It's very hard to make it on the run for that long, and wherever you stay, those people could get in serious legal trouble.
I intend this answer to be for general information only and it should not be substituted for advice from an experienced local lawyer who can investigate your situation fully. Contact information for all attorneys on Avvo can be found by clicking on their names.
You can likely come up with a more fool hardy idea than running away, but you'll have to work at it a bit. You are on probation. That's a tad more serious than being grounded if you do not know that.
Truth is, most folks your age, on a good day you get a D in sneaky. This means you'll likely be found out, and then, since putting you on probation did not get your attention, there is a real potential that parking you in a juvenile holding facility just might do the trick. And no, that;s not exactly like pledging a college frat early, though there might be some bare skin and paddling involved.