I can't help thinking about marriage?

Ive been Dating this guy for a little over a month now and Ive known him for a few years lets just say its sorta like the love at first sight thing if you believe in that kinda stuff. anyway I know this is more than just puppy love its unbelievable how much im hooked on him that my body goes into physical withdraws when im not around him for over 10 hours. my legs get weak I lose most upper body strength my head feels like its bigger/heavier than the rest of my body and the world spins making it impossible to walk straight.Im a strong nonconformist but i find myself conforming to make sure he stays happy. I am 19 years old going on 20 this october and he is 18 I know I haven't beem dating him that long but i find myself infatuated with weddings and marriage and how I want mine to be. I long to marry him every time I turn on the tv someone is getting married, they talking about marriage, planning a wedding ext. ext. im worried im becoming a little obsessive i keep it all inside ( including my infatuation with weddings) and im wondering at what age is it appropriate to get married and how lng should the couple have been seeing each other?