Should I wait for this Capricorn guy?

There's this Capricorn guy who I've known for like two months.. but we don't really talk much.. and I'm a Leo to the core-- spontaneous.. crazy impulsive.. and just crazy in general--like running around, talking too loud and such.... he's my Professor.. I'm 22 and he's 27.. but I have this intense attraction to him.. and he said that he felt it too.. but it doesn't seem like he even cares.. He smiles whenever he sees me (which he doesn't do with any other girl).. I called him a couple of days ago.. and he said he'd called me back.. but never did.. and I withheld from my impulsive and wrote him a letter instead.. I haven't given it to him yet.. but my question is-- should I? or should I forget about him?