I would post your diet (what you eat every day) in the diet section and we will critique it. Make sure to put the macros (cals, protein, carbs, fat) down. I have always been very thin, but since learning how to diet have been able to add significant amounts of muscle. In my experience 90% of the time the problem is in the diet. Anavar alone is ok if that's what you want to do, I just won't recommend it. What was your last cycle?