maybe try 350mg of soma to start on an empty stomach, then take 2mg xanax
as soon as you feel the soma (20-30mins). then if you think you could go a little more have another 350mg soma. i like to smoke trees, that really just gets me high although some people claim it is a potent painkiller (M.S, cancer, Aids). you could probally drink up to two beers, or a glass of wine or a nice strong mixer. i would ever imagine you would get hungry and it wouldn't be too bad of an idea to eat another 1mg of Xanax, just as long as you can sleep in the next morning.
soma would do the trick without too much high, but you will feel sedation.
xanax would pretty much cause you to forget (or not care) about you muscle pain, and you will physically relaxed causing release of tension from your joints and muscles. you willget high. don't eat more than 2mg if you have to work the next day. go higher and you may need at least 8-10 hrs of sleep (you wouldn't really wake up)and could be sluggish throughout the next day.
just be careful and don't worry to heed someone elses advice, just trying to give my opinion, helping out a novice.