hello and welcome to the forum. and dont mind zilla hes the ball buster around here.
specialblend already said it, a mild trail bike IN SAND against bikes that are long legged, you dont stand a chance. you need some more mods because just switching to some shearers or changing your gearing wont give the checkered flag. Now if you want suggestions on what to do to your bike, the options are endless, just depends on how much money you have to spend. But for about 800-1200 should give you the power you are looking for to be competitive on a play level