Long distance relationship!?

So my boyfriend just left for college today 6 hours away, i have really bad trust issues since ive been hurt in the past..The day b4 he left so yesterday he sent me 20 roses and gave me a bible with my name in graved on it He says he wanted to marry me after the 4 years of college we both have to focus But my question is how can i keep him happy with me? Any ideas on what can i do with out being in person? i just dont want our romance or us losing feelings for each other!