Any tips on how to stop daydreaming about my boyfriend?

My boyfriend and I have been together for about 5 months and its not until the last 2–3 months has it got to more then just friends. We are really close and very much in love. We haven’t been on any dates just had lots of family time together most weekends. He has very strongly expressed that he wants to marry me in the future and has just recently bought a house of his own. I will be turning 20 in December and we feel we should leave it a year and a half before getting married. We are both Christians and go strictly by the Bible. We have had physical contact but nothing more then a little hug. We have never kissed. Also as part of our beliefs as Christians we believe that in order to maintain a good strong and pure relationship it is good to limit contact by phone, email and any other electronic communications and keep it to an absolute minimum. We have promised not to contact each other at all during these 3 weeks and for as long after that as we can.
This is my first serious boyfriend I have ever had. I have only ever had 1 other boyfriend but that was just a school romance.
We are both so in love, so much so that he has lost his apatite for food and we are both constantly tired and weary. We have spent every weekend for the past 3–4 weeks together as family’s and now I am not going to see him again for 3 weeks or maybe even longer. I have a full time job as a sales assistant for a furniture company and sit at a desk all day long. I cant stop thinking about my boyfriend. I have to keep looking at pictures of him and dreaming about times we have had together. I cant even concentrate on my work.
Does anyone have any good ideas to help me to stop thinking about him and concentrate on my work?