Girlfriend blaming me for cheating, am I trippin?

my girlfriend of 4 years and i are both 18. I’m in AIT for the army and will be getting stationed the beginning of next year, so we have already spent some time apart and will be spending even more apart. Since I’m at school, I’m on a very busy schedule (basically busy 4 AM to 7 PM) but I get some chances to use my phone during that time and text her every chance I get. And call her once I’m able to. I just found out from someone she made out with another guy a few weeks ago. When I confronted her about it, she said I wasn’t making her happy anymore and that she wasn’t happy with our relationship. The separation has been really hard on her and I would always ask how she was doing and she’d never open up to me. All she has done is tell me how it was my choice to join the army and I knew the separation would affect our relationship and how she isn’t happy at the moment. Basically I’m just asking for advice because I’m young and don’t know what to do.

Girlfriend blaming me for cheating, am I trippin?
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