Will spermatocele kill me if I don't get treatment?

No. Spermatoceles are often painless. They just make a lump. They won't kill you but they can be uncomfortable if they are large and causing pressure. You don't need anything done if it doesn't bother you just make sure it's a spermatocele and not a tumor in the testis!
No. Is a simple cyst of epididymis which lies on top of the testis. Epididymis contains tubules which carry sperm between testis and vas deferens (sperm duct). Spermatocele is a cyst formed by an obstructed segment of an epididymal duct. Maybe tender to touch and can enlarge so u may wish to have it surgically removed. But it will not kill you.