First of all OP, I want to tell you that AIBU is the wrong place to post about teenagers when you’re at the end of your tether and having problems. Responses will be from people who have never had a teen and have no idea or those with perfect teens. It’s not a good place to post for your own sanity.
Second, what you did wasn’t great, but I don’t think it’s abusive or any of the other hysterical things people are writing. I can see you were frustrated and sneaking into your room to look for confiscates items is in no way appropriate. My DD went through my drawers at 14 looking for the confiscated wifi and I lost my shit! If it didn’t belong to the whole family I may have been almost tempted to smash it too!
Parenting teens is REALLY hard. You are starting to realise you have very little control of them and their choices, and punishments that worked when they were younger are now ineffective and useless. It’s new and a bit scary and we are all going to fail and make mistakes sometimes because we mostly have no clue what we are doing. I’m sure if you had thought about it for a bit you could have come up with a solution that was better than smashing things, but in that moment I can see how it escalated quickly and you shouldn’t beat yourself up. You’re not a bad parent.
Yes I think you should apologise to him, but he should apologise too because his behaviour was frankly appalling. You don’t go through your mum’s bedroom looking for things.
14 is still a child and needs boundaries. I’ve had some success recently with no showing any anger. My kid has pushed my buttons ten ways to Sunday lately and calm and collected chats seem to be having more affect than yelling and punishing. It’s really hard, because sometimes I just want to scream “WHAT THE FUCK WERE YOU THINKING?”, but that wasn’t working either so I had to change my strategy.
You will survive this somehow, you will make mistakes, but that’s ok. Please don’t listen to the posters calling you abusive, I can see that you care about your son, otherwise you wouldn’t be on here asking for help.