She says she has lost feeling for me because she is going through tough times?

I'm in the navy and I been talking to this girl since late December as friends. She had a man in the marines but they broke up cuz of his infidelity. We started really clicking by January, although we live in opposite sides of the country when I have a chance to take leave we see each other. Last time I saw her was in April and everything was great, although she stated she didn't want to be in a relationship because she wasn't ready, and I respected that. Ive met her family and they are awesome people her mom loves me. I then been on small deployment out to sea and we been mailing each other back and fourth. When her grandpa passed away I could do nothing but call her and show her that I'm there to listen to her and that I care. Since then we emailed each other less and less and when I told her I was coming back home she didn't sound excited about it. I then told her I would call her when I pulled into port. But when I tried calling she didn't pick up we went for three days without talking after me being out at sea for over a month and a half. I thought she would wanna talk to me but instead of giving me a call back she would just text me .but then she would send me text saying that she misses me, but never calls me. When I tried talking to her about us and that it seems like she doesn't feel the same nomore she claimed that I was just being paranoid. Whenever I asked if anything is wrong, she says everythig is fine that she is just having a hard time with school and work. But the other day when we talked it slipped out of her that she had missed two weeks of school. I been feeling like crap because I really liked this girl and I thought we had something special but there was no communication and things changed ot of nowhere. We never argued before or anything. Yesterday I grew tired and I asked her if she still felt the same for me? And she said not really due to the fact that she's going through alot in her life. What should I do? And what does she mean by that?