I've used my slow cooker regularly (never for cake though - will have to try that next time we have a cake-related occasion!). What I like best is converting complicated roast/braising recipes into simple one-pot meals.
For example, tonight's dinner features a local grass-fed cut of beef and a recipe from the Good Meat book by Deborah Krasner (amazing reference and recipes). However, like most recipes of this type, the instructions would have me dirtying up multiple pots and pans - marinate this, brown that, reduce sauce, cook the vegetables separately, blah, blah, blah. My method: flop the meat, broth, wine, veggies and spices into the slow cooker, set on high, and walk away. Flip the meat over after about 90 minutes, then continue cooking until done, removing the lid as needed to let the sauce thicken. Less prep, less standing over the stove, and a lot less cleanup.
This simplifying of recipes feeds into the self care thing too. Do not feel guilty or worried that you're going to have a sub-par dinner by simplifying the cooking method. You do not need to spend 3 hours preparing and then cleaning up after dinner when you could spend 30 minutes and get the same result.