I need some help coming to terms with a decision not to take a promotion that requires relocation. Maybe this is also just needing to get it off my chest to people who may understand better than most people close to me.

Long story (short?) - about a year and a half ago I was brought in to discuss a potential promotion within my department at a large global company. Moving from a location-based to a regional role. This would have allowed me to continue to work from my current city which I love and travel intermittently which I have been doing for the past two years. It took months for them to post the positions on the internal board, months more to begin interviews, and then once that was done we were having a rough year financially and there was a hiring freeze. Now, it seems they will not be filling the positions for the foreseeable future. The only other person who held my title within this region (who also applied to one of the three new regional roles) left the company a few weeks ago to relocate to the area where she would have been based out of if they filled the roles. I am now stepping in to support her location (the largest in the world) while a decision is made for how to proceed.
They want me to take the role to replace her, but it would require moving across the country with my husband and small children.

I know people do this all the time, but we absolutely LOVE where we live and our community. All of DH's extended family (minus his sister) live within a few hours and we are very close to them. My brother and SIL also live within a couple hours. The friends we have here are lifetime type of friends.
Add on top of that my mom was just diagnosed with stage 4 cancer and there is a chance she and my father will move back to our state (though there are no firm plans) and I will be devastated if I move away only for them to be back home. Side note - the new location is equally as far a drive/flight to them now as our current city.

I am so sad to say no to this opportunity. DH very, very much does not want to move. I am open to it to an extent but that's because it's my career development that is directly impacted. My VP came to talk with me about the position yesterday and I haven't given my final answer but I know I need to be in this 100% for it to work on both sides (mine and the company) and I'm just... not.

I cried myself to sleep last night and I am tearing up now even thinking about it either way - whether I say yes and risk our family peace and connections, or whether I say no and give up this opportunity.

My decisions feel like they're based on fear - fear of missing this kind of chance (and income) again, fear of putting my family through a potentially really difficult change, fear of taking the job and then regretting it. I don't know how to get past this part and feel good about prioritizing my family over my career. I am just so afraid that nothing will work out in my favor here - whether I take it or not. I need to let this go and trust that things will be fine but I don't know how to do that.