Am I incorrect about this? (punishment)?

Hello. Im a 17 year old high school student. I recieve very good grades, I dont get and trouble and i am basically in check when it comes to school. I dont go out much, and it can get rather lonely, and sometimes depressing considering the lack of social and respected attitudes in the school. Nevertheless, i can say i am getting bored and extremely done with school. But here are my flaws. As of late i have been very forgetfull and i have been losing a lot of things and closing myself off from others. i can be lazy and put off. But i still get the work done. I just can't focus at times. I believe its the stress of paying for college...so on and so forth. At a recent parent teacher conference, my mum wanted to come and get my report card. No problem. I went home to change clothes and i would wait for her to come to the school. But i brought a friend with me. My friend was really complaining about coming in the house even after i stressed the fact guest are not allowed to come in when mums not home. But she insisted and it was hot so i told her only for a minuet. I have severly stressed the rule to others before, but i figured im not having her over for a party and drinks and i would leave. Ironcially my cell rang up my mum while i was inside chatting with my friend so she heard everything. Now im grounded for 3 weeks. I had asked her to excuse something important but she said no, brought something else up and i am now grounded for 1 month instead of 3 weeks...Its not working. I simply feel like i cant do anything right or im not allowed to do anything wrong because i got caught so.....redhandedly it makes me want to rip my hair out. I mean really my phone called her. karma? But punishment, I dont feel the point anymore, and today she said its until i appreciate my freedom....What freedom!!?? i barely go out. only for dance and capoeira, but thats for college and fitness. THATS IMPORTANT. but now shes taking everything away and i feel as if shes doing it for anger not to make me learn anything. She thinks i dont get it, and shes really quick tempered and strict. I feel this is foolish. Am i wrong?