Worst Arguement

I have gotten to several arguments with people in my life. Most of them small but there was a couple big ones. One of the biggest arguments I have gotten into, that impacted me a lot, was between me and the person who was my best friend at the moment. The arugunment started out of no where. I thought everything was going fine in our friendship. Me and her never really had a big argument before. She texted me one night and wrote me a whole paragraph on how she said I changed. She said  that I was acting differently now and that she didn't want to be friends with me anymore. I found it so weird because I didn't see myself changing. I couldn't recall a moment where I ever treated her bad. I was always there for her no matter what. For a really long time I tried to save our friendship and I tried apologizing for whatever I did wrong. But it never went back to the way to was. Sooner or later me and her stopped talking. This arguenment made me realize who my friends are. Even if I did change like she said I did, I have had friends who have stayed with me through it all. Not caring if I changed or not. But, suprisingly a couple weeks ago, the girl I got into an argument with texted me. She apologized for everything and me and her are okay no. But our friendship will never really be the same. This is one of the biggest arguments I have ever gotten into with someone.