Sometimes, I dont feel like a Team Leader

Long story short, I was promoted from Junior Accountant straight to a Team Leader role(I am the youngest Team Leader in the company). My job makes me feel like I am not a Team Leader sometimes., simply because I am doing so much of the heavy lifting when it comes to the work that needs to be done. We only got someone new recently so at least It will keep a balance but I have been working to the point of exhaustion. My Manager has been happy with my progress, My team respects me and they really try to help with the work. One colleague that I lead has been amazing help by filling in where I cannot sometimes.

I dont know what it is but even though things are generally not that bad, I feel almost as if I am not doing enough to lead. My team for the most part is independent (a few exceptions there and there) and I help them get over the line every month. I guess its because I assume that I should know everything when thats not what its about because I know for sure that I lack knowledge in certain areas.