i don't know what to do

So i have auDHD and depression+anxiety and am currently in my last year of highschool.

i have two friends i left behind at public school to do online. one of the reasons I left was because I knew they weren't very present as a support base, and I felt like the odd duck out. it still goes that way, and I understand they have their own lives and responsibilities..it's just that I get sad when the amount of love and effort I give isn't reciprocated.

I'm currently going through a depressive episode and some health issues that I opened up about, but still no response from my supposed best friend. i feel isolated and alone, as my family isn't very understanding of mental health either. i know how I feel, but I don't know what to do.

do I make new friends? if so, how?