I am an MMath student, about to start my 4th year at Exeter University doing a Mathematics degree. I've always been appealed by the idea of doing a PhD and helping to directly advance the subject, and people have always envisaged me to be a very good person to take part in academic research as I have been renown for getting exceptionally high exam results, generally liking my subject and being willing to help out others. However, since coming to university, I feel like I've been running out of steam, and my performance has dipped slightly year to year, due to time with housemates, poor time management and a lack of discipline to get work done. I am currently doing a summer project with my personal tutor and my motivation has been somewhat low recently even though the topic has the scope to be very interesting, and it's taken me a fair bit of time to produce not very much. My work ethic has considerably slipped as well, and even though I know a PhD would be great for me, I don't really know if I'm in the right mindset to do one right after I finish university. This is sort of strange as I was in a very dedicated and committed mindset before I came to university, yet it's disappeared when I need it more than ever.I'm getting a gut feeling I should maybe get a 9-to-5 graduate job in order to get a better sense of discipline (e.g. having to go to work at 9 bang-on rather than putting off research and doing it at home) as I don't really feel university has helped me that much with being organised or doing well, and even though I have gotten a 1st on average in my degree, one of my modules was only 51% and a lot of the coursework was dealt with in a very laid-back manner (even if it ended up getting put off). After a conversation with my personal tutor about my progress with the project so far, and having not been able to do much this week, he hinted that if my mindset was as it was now, I wouldn't be a very good PhD student - and to be honest I actually agree with him.Is it a good idea to go into a PhD straight after doing a Master's degree or to take a break for a while afterwards? I worry that I'll burn out even more doing a PhD and if I carry on at this rate I probably won't enjoy it as much as I should.