How do you navigate through career fears with a rocky relationship?

Hello. I (26f, swe) work in tech. I've hit a sort of a rough patch (going on and off for 2y) with my bf of 4yrs (25m, also swe). I recently got a promo at work.

That relationship anxiety has started to bleed into my work. I have become forgetful, am underperforming. I am hating how I'm working, pretty sure others are seeing it too. The underperformance is filling me with dread. To an extent that I can't open my laptop. I have lost interest in my hobbies as well. How do I navigate this?

My priority right now is to get back on track career-wise. I like this job. It has been 1.5-2 months since I started going off track like this.

For context I have other interests as well. I go to the gym 3x a week and run 2x. I bake. I crochet. I watch tv. Have friends (been unable to speak to them since the rough patch). I like cooking and reading as well. What to do?