Undecided

I have been at my job for 17 years. I think I am pretty good at it and very comfortable but a new higher position at my work has opened up. I think I want it but it is a lot of new learning and I'm not sure I will get the job because all the other Service Managers in the company are male and have been for the last 75 years. I don't mind the learning new stuff. For the last 2 weeks I am trying to do my job, organize the mess that was left, and learn fast what needs to be done in that position. I must say the days have been flying by. I have been going to school to one day take over that office but I thought it would be 5-10 years down the road. One minute I want the job and the next I wonder whether I want all the new responsibilities. I kinda like that I know almost everything about my current job and have set hours. 7-3:30 works out great for me because I go to school in the evenings. I am also afraid that if I get that office organized and back to functioning and my company hires someone else after all the hard work I have been putting in that my feelings will get hurt and I will quit. Or at the very least have a very bad attitude toward the company(I currently love) and any new hire. I would have to deal more with Joe Public and not sure how well I would like that but I already know most of our customers and doing more than my fair share of that job anyway. I feel like such a flip flopper. Do I or Don't I?