Materbation help

I have a vibrator that’s nice and tiny and it works great and all but I want some good penetration. I’ve tried fingering but my arm gets to tired for me to do anything longer than 20 secs and the hairbrush handle is to small. I can’t buy a dildo because I’m underage and it would be SO embarrassing if I ordered one online and my parents found it in our mail😱what should I do?

-sexually frustrated