Always stressed !

Hey lovley mums
I work a full time 9-5 job , have 2 kids ( one is mine miss 6 and one is my brother who's living with us 12 ) and my partner ( miss 6's dad ) , I just feel like I am constantly stressed and trying to remember everything and am just failing , my partner doesn't help much with the kids or the housework which causes a lot of fights , he and the kids are messy , every time I turn around the house is a mess and were rushing from one place to another with no time to clean , My brother has autism and everything with him is just difficult and I find my self loosing my temper a lot , miss 6 is struggling at school and with limited time at home to get things done there isn't much time to help & my partner has no money concept he just spends everything he can & just wastes money with things like energy drinks & leaving the aircon and fans on when nobody is home.
I am just so stressed about everything.
I'm just really not coping well at all.
Any advise would be greatly appreciated.

Ps: sorry about the long post.