hi!
i used to be in your exact situation 6 years ago, i was 21 and 113 lbs, i have very small bones, and you probably do too, i have thought about steroids at your weight too, but they would have added on 20 temporary pounds (best case scenario) I would have lost everything and fucked everything up. I am now 27 and I weigh 210lbs. I have been training like crazy for 6 years without a drop of gear, and I got up to 190 lbs, but I looked bloated because I would eat so much.
Then I lowered my carb intake, and cut it down to a nice looking 175 to 180 lbs.
Then I got frustrated by not making any new gains, and after 6 years of hard training and eating like a horse I started gear and now it makes A LOT more sense as my gains have been incredible!
Just eat, and don't stop, get stronger, lift heavy, it really doesn't matter what you eat at that size at least it didn't for me. Just try and stay away from junk and alcohol.
Don't compare yourself with others, that helped me a lot, you just need to realize that you are not at the same point.
When/If the time comes for you, please have the maturity to man up to needles or just do not start anything, i see many guys around in my gym that fear needles do only oral cycles gain temporary strength and size, come off lose motivation and end up at square 1, you are just going to be doing so much damage to your body for no gain at all. Also many guys whine like bitches about IM pain, but I swear to you, if you know what you are doing, it isn't that bad at all.
Please consider these things before starting any cycles at all, at that size you will not gain anything with steroids, I know sometimes that patience is not an easy thing but in the end it pays off.
Don't give up man, there is hope for skinny guys too. You just need to really want it it took me almost a decade to gain 100lbs.
PS: PLEASE STOP TELLING HIM HE HAS MEDICAL ISSUES, THAT IS SIMPLY NOT THE TRUTH.