How do I stay steady with angry parents and school politics?

You have grown into the role. You can manage the community, handle the day-to-day. What still rattles you are the angry parents and the politics, the moments that get personal and loud. That reaction does not mean you are not cut out for this. It means you take the work, and the people, seriously. Remember what is underneath an angry parent. Almost always, it is fear for their child. The heat you catch is love with nowhere good to go. When you hear the fear instead of the volume, the attack becomes a worry you can actually respond to. It stops being about you and becomes about the kid you both care about. Before the next hard conversation, settle yourself with one line: this person is scared, not evil. Then listen first and answer second. The politics you cannot always control, but you can control whether you meet heat with heat or with steadiness. Steadiness is a practice. You get better at it every time you choose it over reacting.