First relationship out of a divorce and in the military

So long story short, I dated a women from 9th grade all the way until we got married a year after highschool when i joined the military. We were apart for all of basic and my training and then i got stationed in England. It took her 4 months to get there because of passport and visa problems. Unfortunately shortly after she got there i deployed. 6 months into a 9 month deployment she left with someone who i thought was a great friend of mine. There wasnt any warning or anything like that. Just up and left. So i got divorced jan. 2014 and didnt start seeing someone until april (we were seperated for about a year before the divorce was finalized). now again, shortly after we start seeing eachother i have been told i have to go to retraining about 16 hours from our hometown away from Jan until May. so its been about a month that ive been here. Im currently really having a tough time trusting her. Not that shes given me any reason to not trust her but just from the past. I feel like a terrible person feeling this way. And she has mostly guy friends. Well.... almost all guy friends. I get worried that some of them will take her kindness as flirting and we all know that for a lot of people, knowing the other person has a significant other, they will still try to sleep with them. I just dont know how to handle all of these feelings. I'd like to bring it up but i dont want her to take it the wrong way.