At age 17, you are not only too young to be on the juice but you are also too young to be on this board. The TOS says 18 and older.
However I will leave it to another mod to make the call on what to do with you. My advice here is that you totally forget steroids right now. Throw that out of your head completely. Because it will just be a disappointing short fix for you that only robs you of your future gains.
Instead take the money you were going to spend on roids and ancillaries and purchase WEIGHT GAIN powder.
www.proteinfactory.com is the best. Don't worry about whey specialty powders, just go for overall calories.
You should be taking in 1.5 grams of protein per bodyweight. Then you need at LEAST 15 total calories per lb of bodyweight.
So in a nutshell :
Bodyweight x 1.5 = daily protein intake.
Bodyweight x 15 = minimum daily calorie intake.
Training wise, you are going to need more intensity for shorter durations and also more recovery because your body is already changing and adapting at 17 y.o. If I trained you, I would put you on a program of H.I.T. or Dogg Crapps method. You can do a search on here and find links to those websites that explain the training methods. DoggCrapps post Cycling For Pennies is a great read for the overall knowledge and explanation of how to make your efforts, diet and recovery come together.
Hope this helps you. Sorry I can't tell you to take a magic pill and everything will be better, but you will find more truth in my words here than you will in cycle you may do.