1. You are too young. don't screw up your natural test. 2. You are too small. Get your diet right. Its hard to do consistently, but that's the only way to add muscle mass. 3. Test only for first cycle. I'm not a big fand of blends like sustanon, but some guys really like it. 4. get some blood work done and address any gyno and other hormonal issues with a real live doctor way before taking AAS. good luck.