Desperately seeking relationship advice. I'm new to this.?

Just lookin for advice and input from anyone and everyone. I've been in 5 relationships in my life, 4 in which never lasted more than a month and it ended with me always being cheated on. My currnt relationship just took a turn for I would say the worst. We've been dating for 4 months now. We useto hangout everyday and we spend the night everynight. She's the type of girl that won't cheat on anyone and she always told me to not compare her to my exs because she is not like that but it's so hard when all I ever been in are cheated relationships. Well recently we've been arguing quite a bit because I want to spend as much time with her before I deploy for 400 days and we've already gone ring shopping. Well she has alot of guy friends because she hates girls and their drama and well I dislike it when she's around guys. She's just been less affectionate the past couple weeks and I asked her about it and she said she hasn't been in the mood or just want space. She said that she feels overwhelmed and wanted to take a break from eachother for 2 weeks but according to her neither of us can go out on dates or get with anyone. She said we aren't together and she would see me on the 23rd but in the meantime we'll go out and do our own thing. She reassured that she won't get on any other boys. She said this break is so she can relax and calm down and to stop whatever emotional rollercoaster she's on. She said she has no feelings for other guys and doesn't know what's wrong with her or what's causing this. What should I do, what am I to think or what does this all mean? I'm 23, never been in love till I met her and I feel like my world is crashing down on me. I try to not think about it or her but she's all I ever think about and wonder and as much as I want to believe her, It kills me to think that she's in the presence of other guys. Sorry this is long but I need all the advice. I don't want to Lose her.