I'm just over two years in and I have been feeling like this for the last 6 months. I have no motivation whatsoever right now and I'm stuck in a cycle of guilt and apathy. It's so frustrating because I've never felt like this before, I worked really hard on my first degree and my masters and got good results. I just feel stupid and lazy. It's even harder to motivate myself as I know what I want to do career wise now and I don't need a PhD to do it. A few people I have sp