brasstacks

Hi all I have a Milwaukee 28v right angle drill that I use on a winch to trim sails and haul me up the mast on our sailboat. Lats week the ability for the drill to perform at a variable speed quit on me. Pulling the trigger, it was either full speed or non. It also got stuck at full speed a few times. My question is has anyone familiar with this problem, and if so is it something I could fix or would I need to send it off to Milwaukee. Any input much appreciated. Phill