Bié jíjímángmáng de, xiān bǎ shìqing xiǎng qīngchu.
Don't be in such a rush — think things through first.
Tips
grammar
AABB reduplication of 急忙 ("in a hurry") — this pattern intensifies and adds vividness, common with disyllabic adjectives/adverbs (e.g. 高高兴兴, 干干净净). 急急忙忙 modifies a verb, almost always followed by 地: 急急忙忙地走/跑/收拾...