The phrase "get into a dither" means to become nervous, agitated, or confused about something. Antonyms for this phrase would be words or phrases that suggest calmness, tranquility, or clarity. Some antonyms for "get into a dither" could be "stay composed," "remain relaxed," "keep your cool," "be at ease," "maintain equanimity," "keep steady," "stay focused," "keep it together," "be confident," or "stay unflappable." Using these antonyms in place of "get into a dither" can help convey a sense of calm and control, and can help individuals maintain a more positive and productive mindset in challenging situations.