I know you mentioned that you cannot exercise, but with a dog to take of, maybe you can work with that. I'm not saying take long walks down the street and around the corner. But maybe to the end of the driveway and back (assuming you have one), or to the next house and back. Start small, baby steps, because the Vitamin D from the sun can help. Trust me, I was pretty much vitamin D deficient and between being out a few minutes more and taking suplements, I think has helped my mood. And maybe the fresh air will give you some type of inspiration for other possible activities. Not sure if that makes any sense or if that helps, but I hope you are able to find what you're looking for.