What is wrong with him? boy advice?

I recently met this guy at a party we hanged out and danced , he asked for my number and after we starting texting. i am older then him by 2 years. his 16 & me 18. He fell off this dirt bike and i went to see him in the hospital. he lives far away but i did it cuz i really like him. so i was there hanging out with him in the hospital and we were talking more about each other he then asked me to be his girlfriend i said yes. since he lives far its kind of hard to see him often. so days later i invited him to an event to see he again , he couldnt go then days passed i didnt hear from him then it was my birthday he knew about it and the day he asked me out promised to take me somewhere but didnt call into the night his excuse was his phone didnt work/broke. i said okay and the next day i still didnt hear anything from him no call or text. im wondering whats wrong? i have him on facebook hes always going places but not inviting me into that exacult moment. guys why would he be like this? is he not talking this new relationship seriously? we barely have one week going out and the last day i seen him is the day he asked me out? advice please?