How Can I Ease My Mind ?

So my boyfriend of almost 2 years is going off into the army ....last weekend was the last time I'll be seeing him for a while and I'm just so scares that he'd going to forget about Mr even though he days he's not ...he talked about marrying me and wanting to do things for me that he couldn't before he got this opportunity and he says he's going to wait for me ....part of me believes him 100% but the other part of me is too scared to ....I'm scared that I might end up losing contact with him ....I'm scared that hr may find someone better than me...I'm scares that he might not come back .....it breaks my heart to see him go but I know he's doing this to better himself and be the best man for me in the future and prove everyone wrong who doubted us .....I'm haply for him and I'm going to pray everyday that he is safe and he comes back to me alive and healthy but I'm just soo scared ....the military is very dangerous depending on what your trying to get into with your time being there but I just hope that I'll be able to hold him in my arms the same way he left .....its going to be hard but I really love him and have faith that he will cone back for me like he says he will .....I even left my jacket at his house and he left a note in it when I got it back and I cried .....is there anyone else in my position who can give me advice or an ease of mind ???