Huge vein on top of penis not going away after 4 years from masterb too much. now curves when it gets hard. how do i make it go away without surgery?

Unclear, more info: Large, prominent veins of the penis are not abnormal. Maybe you have penile sclerosing lymphangitis, which causes a firm cord. The cause isn't known, but probably not masturbation. However, if you mean your penis curves when erect, that's a different and more serious problem, probably not caused by a vein or PSL. Surgery may be necessary. Discuss further w/ urologist or get 2nd opinion.