Misaligned marriage timelines and future goals. What to do?

I (M, 27) am in a 3-year long-distance relationship. We meet 2–3 times a year. We recently had a discussion about getting married, and our timelines don’t align at all. She (25) needs at least 6–7 years, while I want to get married in 3–4 years max.

Also, settling in the same city will be an issue, as I am an engineer and she is a doctor. My job will always be in a Tier 1 city, while she wants to run her parents’ hospital in a Tier 3 city.

The end goal was always marriage, which now probably isn’t going to happen. I don’t see a reason to continue being in the relationship, as it will only lead to a bigger heartbreak in the future.

That said, I am deeply attached to her, and it will be very difficult for me to break up. I care about her a lot, and the thought of letting go is painful. I’m torn between being realistic and staying hopeful.

What should I do? Please be respectful or don’t bother commenting, I’m going through a lot already.

TL;DR: In a 3-year LDR. Our marriage timelines and future locations don’t align. I care about her deeply, but don’t see a future together. Struggling to decide whether to stay or move on.