You struggle to gain weight without AAS you will struggle to hold onto any gains you make. You don't gain at 3000 calories you need to eat 3500. You don't gain at 3500 you need to eat 4000. No doubt you have your diet sorted though for throughout your cycle and then a different plan for pct and then a different plan for after pct.
And there is more to being ready for AAS than your height. ALOT more.