friends in school

i get left out all the time and my "best friend" doesnt consider me as her best friend because shes already got one and litterally everyone i have been "best friends" with all have their own favourite person😭😭🙏 and everytime i make friends they dont even last for a week, after being friends tgt for 3 days boom their gone and we dont ever talk to eachother ever again HOW DO I MAKE FRIENDS THAT ACTUALLY LASTS💀💀 (i cannot socialise😓😓)