If your error cost the game, walking the handshake line with your head up is the first step back.

After a mistake that decided something, the urge is to disappear: head down, straight to the bag, out before anyone speaks. Hiding reads to everyone else as not being able to carry it. Staying upright through the handshakes is not pretending it did not hurt. It is showing that you are still here and still available.

If it happens, do the ordinary things in order: shake hands, say good game, sit with your team. Let the night be bad without adding to it. Then show up early for the next session, because that is the part people actually remember a month later.