This could be anhedonia- the inability to feel pleasure or the things once gave you joy no longer do. This is one of the symptoms of major depression. What I notice is though that everything you list can be pretty boring, I mean they are all inside fairly lazyish activities. You aren't moving and most people turn to these activities out of boredom, hardly anyone has fun playing guitar alone it is practice and practice is usually boring. Try doing something outside in nature, take a walk, go for a bike ride, or sit in a park. If you are able go somewhere social or even a cafe to drink a coffee and people watch. Find a sport or game you enjoy, bowling, billiards, cards, tennis, etc really anything other than sitting in the house being bored because that is what it sounds like to me.