I feel for you. Recruiters giving false information, unfortunately, happens on occasion. I wish they didn't do it, but there are some bad apples out there like any profession. Most do a fine job.
The deployment is going to be tough, but you can make it through. Look at it this way, 6 months is nothing compared to 15 months. That is a back breaker, and to me, unacceptable, but they still do it. In order to make it through this, you must remain optimistic. I suggest making a vow between both of you to be supportive of each other and not fight. Don't get into anything petty and be faithful to him.
One of the hardest aspects of deployment i the lack o information. He won't be able to give you specifics about where he is and what he is doing. He will have to rely on others in his unit for emotional support. Tell him you love him and always be positive when talking to him over there. It will make a huge difference.
Focus on what will happen in the future. You are very young. You have decades ahead of you. Tell him that and also let him know college will be there soon. He will be involved in an important mission at an important time in history. It will give him great pride to have served over there.
Good luck. It will be over before you know it. Try to be constructive in what you do while he is gone to pass the time.