I seriously don't know what to do anymore?

A month ago my mum was mad at me almost every single day, i was doing all of the chores while my mum watched shows and played games on her iphone. When she gets mad she shouts at me for hours, insulting me in every possible way. And i mean… Her insults are so brutal, like you its not just "you're stupid, you're a b*tch, you're useless, your life has no value", she says those things when she is mad but says other really, not good things, lol. And during that time i was planning to move out, i had a place i could've moved to, but then all of a sudden my mum changes into this person who doesn't get mad everyday, and does cleaning. She's never been a nice person for this long, it's been a month and a bit, so i thought maybe she's starting to change? But I really don't want to get used to her being nice, because usually she just comes back as a mean person after a while, and it hurts even more.
Everything is just so confusing.
is it better for me to move out sooner rather than later? I want to live on my own, but my mum thinks i'm definitely going to stay with her forever.

I say go for it. You don't need or deserve that kind of negative/abusive treatment in your life. Especially from your mother.

I understand you probably love your mother but in all honesty, blood doesn't mean S**T if there's no love or respect along with it.

Your mother is probably just using you to do all the physical work for her. She can't afford to let you go or your mother will have to do the work.
Just move.

Plan on college and that will get you away and get you on the right track. Use financial aid loans if necessary, she is probably under alot of stress but you still can't act that way, most parents are not like that so you will have to ignore the insults.

I would move out so you don't have to listen to all her insults