I started a part-time PhD in 2016 while working full-time, and I have just decided last week to switch from a PhD to an MPhil candidature. These last four years have been the most difficult years of my life. I have been struggling with depression and anxiety ever since I started the project. There is a very long list of reasons why, but I won't share these here. I have certainly developed as a person and I now know what I would like to do to lead a more fulfilling and happier life. You need to choose your supervisors very very carefully, and you also need to make sure that this is something you really want to commit to because we are talking about roughly 6-8 years of your life. To be brutally honest with you, I would not recommend it for most people; however, I don't know you and your circumstances, and as you can tell from the messages above, there are some people who have managed to pull it off. It can be done, but the experience will certainly change your life forever, for better or worse...