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

No. Make sure it's a hydrocele! If it's a testicular cancer causing the hydrocele, the cancer can do you in. An ultrasound will answer the question.
Its full of fluid. A hydorcele is an accumulation of fluid in the scrotum around the testicle. It sometimes goes away by itself, and sometimes can be a sign of a hernia. See your doctor for specific treatment in your case.
No it won't. George bernard shaw lived to a ripe old age with a hydrocele down to his knee, and died of other causes. But who else on earth would want to live like that. Consult with a urologist if your hydrocele is very large and bothers you, otherwise you can live with it indefinitely. Good luck.