What occurs if i injected the vein in my penis with anabolic steroids?

Nothing good: Firstly Anabolic steroids need to be prescribed by physician. They are illegal if obtained by any other means. Secondly you coulod injure your penis &/or get a significant penile hematoma. Thirdly, steroids will circulate throughout your body & lead to muscle overdevelopment & premature aging. In short "a rotten idea".

Amputation: Your penis could be amputated. It's well known that several men have tried injecting different substances into their penis, most leading to complications, some to amputation (look up Cocaine and penis injection, a famous story on google). Hope you don't try it, but if you do, you'll be famous on google as being "that dumb guy".