I am so sorry you're going through this. The sadness changes your relationship to food, yet food can help! I didn't want to go out, didn't want to cook. Chocolate helps, good very dark chocolate. Since I couldn't bear to cook, I ate hummus and lots of great cheese, which felt like pampering myself. You may not want to go out, but let a good friend come and bring a great bottle of prosecco or whatever you like, cook you some pasta and watch funny movies with you.