Don't know what to do

So like last year I felt really lonely and depressed and like I didn't really fit in with my class but like this year I started to fit in and like my depression started to go away little by little but like recently me and my friends got into an argument and it kinda ruined our friendship my best friend and our other friend we got into a fight with our 2 friends who used to be our best friends and like one of the 2 friends didnt really like me and this new girl who came recently before the fight happened because she thought she was replacing us but she slowly started to get to like me a bit but like after the fight my best friend that I mentioned we became closer and she was always loyal and didn't leave my side and we started to become friends with the new girl and become closer to her but like now I feel like the new girl she's taking away my best friend because like they're always spending so much time together and she literally is like always next to her like literally attached to her and like it feels like she's starting to come between us. Like she also likes me but not as much as her and I dont hate her or anything like I get it she's new and she wants to fit in but like it seems like after we became close with her me and my best friend started to slowly drift away and I haven't told her because I feel like she'll get mad and I dont want to risk our friendship but like I feel bad from hiding it from her like I told the 2 friends who I used to be close with and they understood and they said they also agreed but like I wanna tell her the truth but idk what to do cause like she's a really good friend and I don't wwant to lose her and be lonely again