Knowing your BF would help, It just comes down to eating. You simply aren't eating enough, and certainly not frequently enough (in my opinion), try for 6/7 good meals that include at least 220 gr protein and maybe around 3300-3500 moderately clean cals per day (obviously this is a shot in the dark, but a good starting point nonetheless) I feel your pain as far as being tall and very thin. I was @ 6'1 132 lbs in February, I'm now up to 166 lbs (and still at 7% BF), I regretably ran s-drol, but IMO it was a waste because i'm putting on weight just as fast with a good diet, rest, workout regiment as i was while ON. I'd at least wait to cycle until you know what makes you grow (diet/workout), once you have that pinned down, you won't want to cycle because weight will be flying onto you. Increase your cals and frequency of meals and watch the scale in amazement. Good Luck Man!