Kurt Cobain was an incredible vocalist. He's rough and emotive, but his ability to craft harmonies and melodies between his instrument and voice is damn near untouchable.

But to the question, Billy Corgan, Tim Armstrong, Shane McGowan, Joe Strummer, and (earlier) Nick Cave are all examples of singers that are not technically good singers, but are unique and undeniable vocalists. They do all have the benefit of being tremendously gifted songwriters, performers, and giant personalities. Those things go a long way in making up for any shortcomings in technical ability.

Quick edit to say, definitely go for some vocal lessons, get some practice under your belt, build up some confidence, and lean into whatever emotional conviction you have in your performance. If the audience can feel you, they'll forgive a load of less-than-stellar technicality.