First time manager and struggling. Any tips?

I am a young-ish first time manager. Some are colleagues who were - prior to my promotion - the same position as I was, whereas others are entirely new.

The team I am in is a little chaotic at the moment and has both very busy and very quiet days. 

I am struggling to adapt to the chaos and confidently lead a team. I find myself without guidance, trying to determine what I should and shouldn't be doing. 

I am struggling with a lot of self doubt and anxiety. I constantly ruminate over my actions, trying to determine if my staff like me or not. I see others in similar positions to me exuded confidence and charisma. I am told by friends how easily they found managerial work, or how good they are. 

I just feel overwhelmed with this sudden shift in responsibilities. Trying to quell my own concerns, and frustrations around the chaos, and support my team enough - but what's too much? I almost feel lost or alone. 

I would appreciate any hints or tips you have to offer.