It's OK to fight back! I know that it's easy to do the first few times, actually it's scary as hell to do. But you would be shocked to see how quickly people back down when you stand up to them.
Child abusers are COWARDS, they are bullies and they rely on the fear that they instill in their victims to maintain power over them. More than one survivor here can tell you that once he stood up to his abuser that abuser became a blubbering mess and backed off to never bother that survivor again.
Jesse, if you can't outrun them then you're going to have to take a stance for yourself and defend Jesse. Who else will if you don't? I know that probably seems like a terrifying prospect, but remember that many before you have done it at your age, and younger, with amazing results and with great success.
You have the right to defend yourself against unacceptable behaviour, Jesse. Will you?