School vs. Job

Hi, I know I want to make a life changing decision this year, but I am not sure which route I should take so I'm hoping to get some serious advice of what to do. I have been working at my current employer for 5 and half years now and I am getting bored with it. During these past 5 years, I went to school for my MBA so now I have the MBA degree and can pretty much go anywhere. The other side to this story is that I want to retire as a college professor and I believe that having a doctorate would help me to reach that goal. The doctorate program takes 3 years. So right now I am trying to decide whether to take on a whole new job and start my doctorate program a year from my new hire date OR stay with my current employer since it's easy and I could put more concentration on school for the next 3 years to get the program over with. IF I stay with my current employer and finish the doctorate program in 3 years, I will have my PhD and 10 years of solid experience in my field which I believe would definitely help me get my foot in the door at any college as a professor. However, IF I stay with my current employer, I will feel like I am putting my life on hold for another 3 years and remain bored. In the grand scheme of things, I am in no rush to get my doctorate but it is just a matter of starting the program this year and continue to be bored with my current job for the next 3 years OR starting a new job this year and earning my doctorate 4 years down the road instead. Oh and please don't be like my sister and say "why can't you start a new job AND start school this year" lol I work in Human Resources and that is just way too much brain power for me all at once. Believe it or not, HR is a mentally exhausting job. Well, thanks for listening and I would love to get some advice as to what route to take. Thank You!