You're not going to die, tell your parents ASAP. If for whatever reason you are unable to urinate, your bladder could burst. It's a simple fix, before medical professionals figure out what's going on, they'll put a catheter in you and that will solve it. This is not worth hiding from your parents, trust me. Tell someone close to you ASAP or call 911 (or your country's equivalent) and explain to the operator what's going on.