If you were to go against the advice and start injecting steroids into your body early everybody here would want to seriously smack you across the face and not help you. The advice is there for a lot of good damned reasons not related to age.
You're 118 lbs pounds. You have NO BUSINESS injecting steroids. You need to start fucking eating.
A certain poster on the beginners forum from India started at 6' and 110 lbs. He has gained over 20 lbs WHILE swimming and playing cricket competitively to finance his education (in other words, no ability to cut those activities out like he should have). He did this in under a year. In fact, I believe he did it in under 6 months IIRC.
If he can do it with almost no supplements and roughly 4-5 hours of endurance training daily, you can do it steroid free. If you do not gain 20 lbs of body weight the first 12 months you are lifting seriously, you are doing something wrong. I gained 20 lbs my first year and did a lot of shit wrong.
DO NOT inject steroids. People looking for a shortcut like you seem to be make me want to scream. FUCKING EAT a hamburger or something already. It's your diet not your lack of injectable testosterone.
5x5 strong lifts + food. Or, if you really want to, 5/3/1 + food. Both are good programs and you have zero business using exogenous hormones. The low side of your goal is roughly 154 lbs body weight. You should do that in under 2 years, and really should come close to doing it in under a year given how under weight you are.
There is no "best program" and the only damned diet you need to worry about is EATING every day. There is no special diet for your situation and never has been, its called eating more. You try to "find the right diet" you'll waste a ton of time you could be using to get bigger.