Experience leaving your dog at home because it’s best for them?

I got my dog when I was 22, I'm 25 now and moving out. The issues is my dog is a rescue and had extreme separation anxiety when I first got her, I've been in and out of jobs and school so I got to spend time with her for long stretches, when I'm home she's attached to me. But lately I've been working full time and I notice that when I come home she's spending time with the family members that are home with her more, she'll sit in the lounge or be with my mum and then come to me later when it's time to sleep. I think it's because they sneak her food when they eat and I don't (she's honestly big and greedy) but I'm so torn on finding a place we can both stay at (which is HARD) or just leaving her here, I'm moving about 40 minutes away.

There is almost always someone at home and if there is not then there are 5 other pets (1 other dog), I want to do what's best for her but I also feel like I am what's best for her. They overfeed her, they don't walk her, they don't bathe her. So I don't want to leave her but at the same time my dog HATES being alone. When I leave she stays next to someone the whole day. She hates being alone. I just don't know what to do.