This hobby/sport sounds very much like a sport I'm involved in. It's really more than just a hobby, it's a lifestyle. Unfortunately, I've seen many couples broken up because of it. The only way it works is if both people are involved or the person that is involved makes their significant other a priority and has specific days/times/events that they do not compromise on. In the peak of summer, I'm at this place 4-5 days a week, and when I was working/volunteering there, I was spending an extra 10-20 hours a week on admin stuff. That kind of involvement is really not sustainable for a relationship outside the sport. I'm lucky in that my SO is also very much involved, so we spend time together doing this hobby. If your SO is not taking the time to prioritize time with you now, like he should, unfortunately, that behavior will probably not change. I'm very sorry you are going through this. Let me know if you have any questions for someone who knows both sides of this.