I highly recommend you take an hour and a half to watch this Lynda.com video on Leadership Fundamentals. It's focus is business, but first and foremost we are all leaders of our own lives and the lessons apply as much to personal as professional development. It may serve as a good refresher as to what you once learned makes for good leadership as a manager and help you identify your strengths and weaknesses as a leader of your life as well as in your organization. They have a ten day free trial and there are many videos you can watch after this one that will help you no matter what path you choose to follow. It is well worth the 90 minutes. It helped me understand and resolve a lot about myself and my dissatisfaction with own career, my organization, and what was wrong with both.

https://www.lynda.com/Business-Skills-tutorials/Leadership-F...

Pay particular attention to the segments on emotional intelligence, motivation, engagement/disengagement(!), and professional development. It'll not only help you understand what is affecting your motivation and disengagement, but you may also realize your greatest strength is that you are motivated to solve these problems not just for yourself but others in your organization. Understanding the way things should be could just cause you to double down as a PM and master the challenges of the role while further developing your skills to advance your career.

Good leadership focuses on the health (and happiness) and growth of the individual as much as the organization. Maybe you are just in a poorly run organization or one that has poor leaders. Discontent is usually a pretty good indicator this is the case, because even if an individual is the problem, a good leader has the awareness to recognize this and have a good relationship with their staff that enables them to make the staff member aware of their strengths and weaknesses and the source of their discontent so it can addressed be remedied.

It sounds to me like you want to more authority and control, or at least more challenges and your organization's leadership is not addressing that. Without that your growth and personal development is limited. Being a coordinator is little more being an admin that tracks status and doesn't require much tactical or strategic decision making. Your manager should understand this and being stretching your abilities in every area little by little until they trust you to make those decisions. They should always be preparing you for the next level up. Maybe you aren't aware of your weaknesses and they are not identifying them and working on them with you. Maybe your desire to quit and become an individual contributor is just an Escape Coping mechanism for dealing with stress instead of a Control Coping mechanism which is positive and proactive. Or maybe they just have poor leadership skills.

It would be terrible if you quit your job and lost the opportunity where you are to address your weaknesses and strengthen all of your skills in an attempt to start over because you feel it would give you more control over your happiness, especially given all of the capital you have built up in that role over the years. Besides, if the problem is your desire to leave is a just an unhealthy response to stress or a challenging situation, it won't solve anything.

Just a thought, but one from someone who has been there.

What did I do in your situation? It took me a while but I watched that video, combined my awareness from it with formal knowledge of PMP (Head First PMP is good start) as a reminder of what project management is all about and what my organization did wrong as leaders of a functional versus projectized organization (a weak matrixed organization), and then I studied stress management to help me understand my own (unhealthy) responses to my situation.

If I had done that while still at my organization I would have not only felt empowered by the evidence and knowledge, but challenged to work on myself and the organization at the same time, and could have been perceived as someone with greater leadership potential that would have allowed me to level up. Even if I still decided to leave, I could have improved my skills while there to prepare for a move to a healthier organization that I would have been better equipped to recognize and excel at.

FYI I strongly considered a Masters in Data Science which would have had a narrow focus either as a developer, data analyst, or data scientist, but at the risk of competing with people who were younger and/or smarter, and rooted in those disciplines from an earlier age. I decided I should master my management and leadership skills instead, leveraging and building upon my knowledge and experience at a better organization. I am unemployed and working on that now. Once I get a job, even if it's a contract position, I can still take the online courses to get that masters degree from a top university and also take advantage of being around people in the industry that do what I aspire to do as mentors.

I sincerely hope this helps.