Haven't read this thread, only the first page, but you should sell your stuff if you no longer want to do photography.
If you feel that your work is of a lower standard than it was previously, but you still have a passion to shoot good pictures, then take a step back and evaluate the differences between your old and new work. Frame of mind, time of life, motivations, etc..
If you've hit a slump, then steal techniques, ideas, and concepts from other photographers. Making a great picture, even one completely unoriginal, is far better than making a lousy unique shot.
Your lack of satisfaction from shooting may be a result of your ability to recognise bad photography developing faster than your ability to take good photographs. Some people take the worst shots and love them, so if you're taking the worst shots and hating them, it would, in my opinion, indicate that you've taken another leap forward in your journey as a photographer. At some point, if you stay motivated, you will find a balance.