I snitched on my friend because he was trash talking my best friend

This happened in online school, my best friend(lets call them C) was playing the guitar for a presentation and my other friend(lets call him V) kept telling me how C’s guitar was off tune but C thought it sounded perfectly fine and I did too. So I sent those messages V sent me to C. I told C what they thought about it and they said they wanted to report V to our school gc where all my classmates and my adviser was. I said I didnt want them to know it was me who sent that screenshot to my teacher then C said they’ll just crop my name out of the picture. I was feeling pressured in the moment since C has been bullied like this before and did nothing about it so I said yes. So C sent it in the gc and confronted V about it saying to stop talking about them like that since everyone has their own styles in playing guitar. Then my other classmates joined in telling V that we all know everyone has their own opinions but sometimes our opinions can be offensive to others and its best to keep them to ourselves. V took it as everyone seeing him as a bad guy and V defended himself saying he didnt mean to offend anyone and that people always see him as a bad guy which is why he doesnt stick around with people much then he said he was done and left the gc. It got to the point my adviser eventually saw the messages in the gc and asked C in dms(C told me our adviser messaged them) who sent the message, and C said they didnt think our adviser was gonna tell the gc it was me who sent those screenshots, so C told our adviser it was me. Then my adviser decided to call me to talk about what happened, I made up some excuses why I would call to talk to him and he said he’ll talk to me tomorrow. Then V decided to message me, saying how he knows I sent C the screenshots and he forgave me for doing it. Then V proceeded to talk about how no one understood him or got his back. He vented to me about how he thought of himself as a terrible person and that everyone villainizes him and I felt terrible, I was sobbing at this point since I hated conflict and drama. I tried to explain to him how me and my class just wanted to educate because he made a bad choice by reacted that way to my C’s performance and C took offense to it. Me and V talked for a few more minutes going back and forth, he was saying how he was a bad guy and everyone probably hates him and I was saying how we just wanted to help and educate him since everyone eventually makes bad decisions in their life. At some point he just seenzoned me and went offline, now im over here writing this while sobbing and regretting ever sending that screenshot to C. I was only doing what I thought was right, C had the right to know someone was talking about them like that. I dont know what to do, im scared for tomorrow since my adviser wants to talk to me and im not really good with confrontations so I decided to find a confessions website and just let it all out to hopefully make myself feel better.