Should I be embarrassed?

I’m a senior in high school. I go to a relatively small school. There was a new kid and I thought he was cute. Turns out he’s a freshman. Even after finding out I’d figure I’d message him anyways. We have a mutual friend so I got his Instagram from them and messaged him. He was very short and kind of rude. He finally kind of went off and asked why I messaged him talking about how he’s so much younger. Should I be embarrassed for messaging him... I usually don’t message the guys I like because I don’t like rejection. Should I not have messaged him?