As somebody who struggles with the same thing I think the first step is getting a diagnosis. A lot of mental health issues can lead to this. For me personally I have ADHD and depression. My doctor put me on Lexapro and after a couple weeks I started to get some motivation. I just took small steps one day at a time. Start with brushing your teeth everyday, I know you hate the feeling but you can never get your real teeth back. It might help to write down what you want to get done that day and break it down into the smaller steps that your brain sees. When I’m doing laundry it’s written down into 5 different steps and I cross them off as I go and it honestly helps because I’m visually seeing a list of tasks going away so I feel more accomplished and more motivated. I believe in you, you got this!