Need advice

I need some advice. My best guy friend I've known since I was a kid has admit his true feelings for me. He sees me more than a friend. The thing is it's hard for me to explain how I feel for him. I'm thinking I'm falling for him but I don't know if I'm in love with him. I mean lately he makes me smile, happy and laugh, also had a dream about him last night which was a first, I'm always looking forward to him texting in the morning. My heart skips a beat for him with all these things. How do I know it's love and not something different like lust?