Reverse what you did
Thank and release anything you called, usually in reverse order. Open the circle by tracing or walking it in the opposite direction to your casting. Say plainly that it is finished.
Come back to the room
Eat and drink something. Put the lights on. Move the furniture back. Wash up. The mundane bit is part of the ritual, not an interruption of it.
If you feel odd afterwards
Tired, tearful, wired or oddly flat are all common after concentrated attention and mean nothing sinister. Food, water, daylight, sleep and ordinary company are the usual fix. If something persists or worries you, that is a matter for a doctor, not for more wards.