I agree with the point of view expressed by Paxiled, and but also Zack has interesting tips for distracting yourself and changing your behavior by avoiding the stimulus triggers so that you do not use masturbation as a way to avoid relationships and as a way to control anxiety.
Back aches are probably unrelated to the Zoloft but if a problem, see your doctor.
you are experiencing one of the main effects of zoloft which is a stimulant effect, and it is probably what is helping your depression...you should get used to it and it not bother you in another week or two.