Am I just a bad overthinker

I’m currently a freshman in college after taking a gap year. I met this girl over the summer who I had a crush on in highschool we hit it off over the summer and started dating and I see this relationship being very strong and lasting a good bit. The part that scares me from time to time is the life gap, she is only two years older then me but she will be graduating college in the spring and I will only be going onto my second year of school, I fear that the difference in the points of our lives could cause us to eventually break up. Am I just being anxious for no reason and making this gap a bigger deal then it is ? Please just help me out with what you guys think, share your experiences with relationships with gaps, or just let me know if I’m being straight crazy. Please anything will help I rarely get anxious but sometimes this does just become a thought in my mind that doesn’t go away.