Feeling like I have an impossible choice.

For context I 25M have been with my partner for 5 years now. I truly love her and we have a very good relationship (with minor issues).

I've been recently very depressed between working in an unfulfilling job and general life struggles. It's led to me becoming more distant with people including my partner and overall my personality going from very bubbly and outgoing to much more reserved.

I've been recently offered a very exciting job in an area I know I would enjoy living in that's 8 hours away. I would move there for a year to 1.5 years. My relationship with my partner would turn into a long distance one and my partner has told me they would hate that and set very clear boundaries and expectations of how the relationship would change (almost framing it as a breakup). They are supportive of me making the move but I just feel like the relationship won't last if I do it. It almost feels like I have to choose between prioritising our relationship or an amazing career opportunity that would help me feel satisfied/accomplished.

Any input, experience and advice would be appreciated. I just feel completely lost