I'm falling in love with my friends and he's super straight

I'm falling in love with my best friend and I don't know what to do... He's not even my type or 'good looking'. He's just such a nice guy and I can't even deal, and I think my single-ness is just fueling the crush. Sometimes I daydream about us cuddling and gives me a semi ;) How do I deal with this? :(