Sad situation need help handling

Cameron
So my boyfriend and I have been dating for a little under a year now and he's a year older then I am (grade and age wise) 
He's been deciding lately if he wants to join the marines, his end decision was a yes and he's graduating his senior year early to go to boot camp.
His boot camp starts in approximately 2 and 1/2 month then he's home for graduation and gone again.
The thing that make me sad though it that he's leaving on our year anniversary and I won't get to see him for 6months and then 2-3 years after that.
But the reason why I'm so broken up about how to feel about him putting himself in so much danger after boot camp once he gets shipped out  is because I suffer from severe depression and the day I was going to end it I met him and he saved me and we've slowly fallen in love, he started living with my family and I due to some family problem with him so we've lived almost a year together and I can't think of how I'll be able to handle these situations with out him.
He brings a light to my life that I don't know I can lose.