Let me break it to you: its time for a mentor. I know that you have been putting in the hard work and the long hours but you have taken this thing as far as you can go. Its not wrong to acknowledge the limits of your own ability; you are only human. It is true that your potential for success is great, but your potential is not great when you work alone. It is time for you to quit the idea of development in isolation: its time for a mentor. The Art of Manliness ran a series on Jack London not too long ago (excellent blog, read it). The include a quote from a 1903 publication titled, Getting Into Print. London admonishes his readers to,

Study the tricks of the writers who have arrived. They have mastered the tools with which you are cutting your fingers. They are doing things, and their work bears the internal evidence of how it is done. Don’t wait for some good Samaritan to tell you, but dig it out for yourself. - Jack London

Let me offer you three reasons why you need to find a mentor:

1. It will keep you humble
2. It offers practical knowledge
3. It connects you to success

Finding a mentor will keep you humble. It is a pride-swallowing discipline that is rooted in the core premise that you cant do it yourself. Many people get hung up on their own pride and are crippled by growth inhibiting hubris. Those who submit themselves to the expertise of others are capable of learning.

Finding a mentor offers practical knowledge. You will learn things that relate to real life and apply the theories of your trade. Books and blogs are great sources of information, however, connecting with an experienced practitioner is a great source of knowledge. There is no substitute for doing it and qualified mentor knows how to get it done. 

Finding a mentor connects you to success. Choose a winner as your mentor and find yourself in the company of winners. We become like those who we spend time. Dont let your insecurities keep you from aiming high. Don't let your jealousy keep you from aiming high. Embrace the humility principle and be stretched. Choosing a mentor who doesn't challenge you will get your nowhere: this is a compromise that leads to failure. Associate with someone whom you respect for the what, how, and why of their work (see Simon Sinek). Consider process and product least you find yourself in the company of jerks.

There are many reasons why you need to find a mentor. I hope that these three ideas inspire you to consider how you are developing as a leader and as a professional. Every successful moment of my leadership journey has been wrought by the tutelage of others. Men and women invested into me when there wasn't much there. They saw something worth while and I am indebted to them because of it. Most of my mentors were older than me but all of them were more experienced. Don't let the age thing stop you. There is someone who can help you take a next step as a leader; don't try to do it alone. Learn and teach within a network of like minded people: find your mentor today.