Do I love him?

I think I'm falling for my best friend. He's an amazing guy and I love hanging out with him. Everyone already thinks we're secretly dating anyways. Only problem is I still love/miss my ex all the time. It's only been a little over 4 months since I broke things off with him. But i still think about him constantly and he was my first love. I know my best friend has strong feelings for me and I think I am starting to feel the same. He makes me not miss my ex as much when hes around and he makes the pain bearable. Im so scared to break his heart anf ruin our friendship. Am I really falling for him or is it still too early to really love again?