Because you feel like you need someone. And he is someone... and you chose him because you don't want to lose someone you're close to, and

you feel as if you'd lose them if you ended things badly in a relationship with them... but this is just my take on things.

but i don't want to date anyone i'm close to right now

i'm not really interested in anyone

i like David

i like Nick

i still love Austin

i still love Sheldon

....

and i think i might like Michael(JD's friend)

Well...if that works then go for it... what was the "..." for after Sheldon?

i shouldn't still love him

why not? he was the one man who knew how to treat you right. That sounds like the basis for love to me.