<human>: Girlfriend and I have been dating for a good amount of time, and everything is going great. We are completely intertwined with friend groups, families, and we have been through tough and trying times together. Arguments happen, but they are never really hurtful, as we strive to work things out the best we can. Regularly we talk about marriage; even our parents openly discuss marriage and "how it will be when you two are together down the road"-type conversation.

We had just gotten back from a wonderful vacation, a week passes, and I go on another trip that takes me away for a week. When I get back, I am welcomed with a phone call to discuss "Relationship Doubts". I am the type of guy that worked my ass off to date this girl because she is absolutely amazing to the core. She is out of my league, but I go above and beyond to put effort into our relationship, as does she. The "Relationship Doubts" conversation began with her talking about how sometimes she has thoughts of us not being together, and they, on occasion, fill her thoughts. These are not every week or every day, but they have happened a few times with her. One thing she said was talking about her wedding day and who she saw on the altar - most of the time it was me but rarely it was not. This "rarely it was not" is what she said has been bugging her and making her doubt what our relationship stands for.

We are not broken up, however, we have some work to do to. I, of course, am not fantastic with talking about my emotions, so me communicating to her comes after long thought. She is emotional on the other end of the spectrum, so one time, for example, she ran over a toad on a golf cart, she cried. That type of emotional.

Of course after this long phone conversation, it ended with how much she loves me, how she doesn't know what she would do without me, how I'm her best friend, and how well I treat her. So, of course, I am confused as to how to move forward from here.

Summarize the given text in a few sentences.
<bot>: GF of 4.5 years has been acting "off", I spoke with her to see if everything was Ok, and she says she is "having doubts" about our relationship and the future.