Struggling with Exhaustion and Self-Care

I'm exhausted, just everyday I'm so tired, people don't understand how much basic tasks make me mentally exhausted and then I spend days trying ti recover from doing basic things, because I still cook and clean for my kids I'm told there is nothing wrong with me because I can do these things, yes I can but the toll it takes on me mentally is ridiculous, my kids are happy clean and healthy but when it comes to me I live in pyjamas barely brush my hair and can go weeks without washing it because I'm just so tired and the motivation for self care is non existent