hello I have been trying to gain mass naturally but it's been impossible, every time I finish a set of lifting I get really exhausted, some times I get that feeling of passing out, the worst of all is that after 3 months of workout I'm not able to lift more than I did the first week of gym...I believe my diet high enough in protein and I have no bad habits, no smoking, no drinking etc... please tell me what product i can take to reach my goal, it can be a steroid or something over the counter, thanks.