What you are attempting is NOT easy.  You already know that.  While I have a masters and not a doctorate, as a college advisor I got an idea of what the doctoral students went through.  Doctorates are TOUGH.  Many, many people don't finish them.  Doctorates are not about the course work.  They are about independent research.  So if there is not something that you are passionate about and want to research, a doctorate will be harder for you. 

What many people do not understand about college is it is not about the student.  It is about the professor.  This is true even for undergraduates and becomes more true the further up the academic ladder you go.  So the MOST IMPORTANT THING is to find a professor on campus who wants to work with you.  When you have that, many other things can be worked out. 

Because most people working on doctorates are already working in the field, distance education is more of a possibility.  There will be more classes that meet at night and/or one day a week.  There will be more online options.  If there is only one university that offers a degree in this field in your state, they very probably have programs designed for people just like you, who live too far away to attend classes on campus.  However, even for an online course, you will probably have to commute to campus at least once in the semester. 

Many doctoral programs have a residency requirement.  It's been awhile since I was an advisor (1999) and awhile since I checked out doctoral programs (2005), so I am not sure how many still are requiring this.  But I remember at least one saying you could satisfy the requirement in the summer. 

So my recommendation is 1) check if the doctoral program is available through distance education and 2) find a professor on campus you are interested in working with and whom you think you could get interested in you. 

Best of luck to you!