Everything Justin said is right. Life Drawing will take your current drawing ability, multiply it by 4, add 11, then take the result and hug it. I wish I kept some of my old drawings around to show what a change it can make over 2 years(two 4 hour sessions a week).
My advice is to expose yourself to many MANY other mediums. Not only will this help you find mediums you will possibly enjoy more than pencils but it will give you some ideas for multiple medium pieces. Right now it looks like you've used pencil, coloured pencil and pen. Try some water colours and brush pens sometime ... or try dropping buckets of paint onto a canvas from 20 feet above it I hear that's pretty fun too.
Good luck with art!