Entering a long distance relationship for career opportunities?

Hi (27F) I’ve been stuck unemployed after graduating in the winter in Canada. Ive been applying to so many jobs but barely hear back but ive finally entered the final round of interviewing for my dream job in my dream city. My partner (29M) and I for years have talked about moving to this city. I let him know I was applying to this position but it’s moved a lot faster than either of us expected. He’s been such a rock for me, and we’ve lived together for over 4 years. There is an added bonus with this city being closer to my family, which is important since my Mom is battling stage 4 cancer and I could visit more often.

The problem is that my partner has been more financially stable the last few years and could have moved without me but waited for me since I was in grad school. Now, roles are reversed and I’m could be moving but the nuance is I haven’t had a job in months and need to start my career and this is the only opportunity that’s available despite my job hunting efforts. He is not ready to move right now or this quickly. It’s unfortunate timing, and he has been feeling left behind and out of decisions for sometime now since I’ve been living in my hometown a lot to help my family since my Mom is so sick. I definitely could’ve communicated better but here we are again and it feels like to him I’m just living my life and he’s at the mercy of it.

I want to make it clear he is wonderful, kind and supportive. We are planning on getting married and want to spend our lives together. I don’t think this would end our relationship but I know it won’t be easy. I’m not sure what to do because this would help my career a lot, but it’s also going to strain our relationship. Any advice would be appreciated.