How can i keep my girlfriend?

i have a girlfriend witch i love so much , & believe she loves me too , we have different religions, shes 4 years older than me , our jobs takes lots of our time, there is no way for us to live together because we both live on a different places & both rents are paid by our companies, she haves a very different idea on making love than me , but we are getting slowly better ,and our love is true and we only get to see each other once a week, what can i do to keep her , i don't wanna lose her , because our life style is not helping .and im afraid we would get bored in future.