I'm confused

So I have come to a point in my life where I've realized who are my real friends and all that, but recently I have been stuck on a thought.

I was scrolling through my Instagram one day and saw a post that read, "most people meet their soulmate before the age of 21". Now, I don't know if this is true but it got me thinking about my best friend and how we fit together in like every way possible. My brother has frequently asked me why I have been friend zoning him so hard and I was like, "what do you mean?" He said that I was treating him like a brother when he clearly has feelings for me. And I guess I dong truly understand my feelings either because yes I get jealous when he's with other girls but I don't want to ruin our friendship. And I have thought about this more because I went to a going away party for a friend and he was there and we decided to go on a drive to catch up because it's summer. And we go on talking and i let him use my phone because his got taken away and I send good morning snaps every day and some are selfies and he goes on to tell my that I'm pretty and I'm like thanks...

I don't know I'm just confused like I guess I could see us in the future but I don't see him as physically attractive. I do love his personality but I'm just very confused. Please give me some advice on what I should do.