The common side effects of oxymetholone include depression, lethargy, headache, swelling, rapid weight gain, priapism , changes in skin color, urination problems, nausea , vomiting , stomach pain (if taken on an empty stomach), loss of appetite, jaundice , breast swelling in men, feeling restless or excited, insomnia , and diarrhea .  In women, side effects also include acne , changes in menstrual periods , deepened voice, hair growth on the chin or chest, male pattern baldness , enlarged clitoris , and changes in sex drive .  Because of its 17α-alkylated structure, oxymetholone is highly hepatotoxic . Long term use of the drug can cause a variety of serious ailments, including hepatitis , liver cancer , and cirrhosis ; therefore periodic liver function tests are recommended for those taking oxymetholone. 
I think the most unfortunate part about the whole thing is just how easily they prescribe it, for people who don’t even have severe acne, or in your case – people who aren’t on the brink of suicide due to the acne. And how they prescribe to teens with regular teenage acne that will likely clear up in a year or so on its own without emphasizing what a risk it really is. Even if they did, it’s been shown that teenagers don’t have the part of the brain responsible for danger perception fully developed – that’s why they tend to have this bubble of invincibility around them. I know I did, maybe it was because I was older when I got severe acne that I realized that it was too risky.