Drum Major Leadership Advice !?

I just made Drum major for my schools marching band, I am only a junior so I will be a two year DM, but I am weak at balancing friendship off field and professionalism on field. I know my friends should understand I cant go easy on them just cause they're friends, and I need to learn how I should balance work with play? I know it might seem stupid to some, but this a serious issue for me. I cant do my best if Im upset that a friend is mad at me for doing my job. But I WILL do my job. Its just confusing...please help?