Welt/Pimple has been here for months. Would appreciate advice to identify and treat.

Have no clue how or why this has shown up on my arm. Is a pimple? Zit? Cyst? No clue what i can do. Going to be honest, i did something very stupid and tried cutting it off, and it grew back exactly the same so i've learned my lesson and hope there is a proper way to get rid of it. Not sure if the photo does it justice but its a pretty raised bump. Please help :-(

u/SaiyajinAvo — 10 days ago