How do you know if youre in love ?

Can you be in love with someone but not romantically? He’s my best friend and I’m not attracted to him what so ever even tho i wish I was cause he’s a great guy, who I care very much about, I’m just a little confused 😭🤣

He’s recently told me he’s started dating someone. And I am feeling all kinds of feelings I never thought I would such as jealously, sadness kinda angry but more at myself for having these feelings cause I know I have no right to be. I also feel like I’m about to lose my best friend I dunno any advice/opinions is welcome.

If anyone’s been in a similar situation please please comment !