YADBU. Parenting teens is emotionally terrifying and exhausting.
(It's also bloody brilliant on a good day.)
It's hard because the issues that affect them are bigger, and matter...mental health issues, friendships, no friendships, alcohol gets introduced, peer pressure, trying to fit in, exams, pressure, going out and about, being vulnerable, uni choices, stress, hormones, love interests and everything else!
The more kids you have, the more issues you have to contend with. It's a roller coaster. You never quite know what they're going to bring through the door after school.
When your younger primary aged kid comes out of school feeling a bit sad after a bad day, chances are, a cuddle and some tlc will make it all better...you can intervene with school, with situations, and you can make it better. Or if they don't get invited to a party, it hurts for a while, but the kids move on.
You love your teen with all your entire being, but they pull away from you. You irritate them, and they don't hide it. They make their own choices, and you want to support them, but can see that it's not the right choice for them, but you let them do it anyway. You do all you can to make them happy, keep them safe, help them fit in, and yet constantly question if you're doing the right thing.
The good days are fantastic...sharing jokes, watching shared interest on tv, them having mates around and hearing them laughing...but the bad days are thankless.