Not gonna lie I hear so many people say I did all the right things and it didn't work. Well the reason is you DIDN'T DO ALL THE RIGHT THINGS. You are too young for steroids in my opinion and I don't believe anyone should take them unless they were going to be a professional bodybuilder or prescribed by a doc. In your post you stated in shape, small/mid beer gut. Well if you have a small/mid beer gut you aren't in shape. Dial in your diet. I swear I tell so many people that diet is seriously 85% the most important thing in training. Buy some whey protein (protein factory 10lb pale!) and take 3 shakes a day along with 6-8 small meals (of good quality food no fast food)
That is seriously the only way to build muscle and yourself. I used to think that I had a good diet until I started writing down everything I ate, needless to say I was shocked that I wasn't eating enough and I wasn't eating good food half the time. You can't build muscle without gaining weight and for that you need calories and protein intake. It has always been extremely hard for me to gain weight ever since high school when I wrestled. I finished Highschool weighing 160lbs. Last year I weight 180-185lbs, and thats when I realized I wasn't doing the right things and wasn't focused enough at all. Currently I'm 211lbs and still gaining. (Currently a mass gaining diet...trying to get up to 240-245 before I cut so my diet isn't the cleanest) Trust me write down what you eat, write down days you trained what you trained and how much weight you were using and post it all in a thread, we can critique and help you out where you need it. And another thing............DON'T TRY TO LIFT TOO HEAVY!!!
Too many people try to impress other people in the gym. If you can't control the weight going up and down 3 seconds each you really have no right using it. I seen a guy in the gym trying to do shrugs with 500lbs............umm he barely lifted the thing off the pins, didn't even get one and looked around like he was he-man while I was doing shrugs right next to him with 255lb. I was much larger than this fellow, so remember its not how much you can lift in bodybuilding. Its more about controlled movements.
If I can do it all natural, you can do it and everyone else can. But it all depends no how bad you want it.