Hexagram 51, Zhèn (The Arousing Thunder): Line 1
震卦初九 · 震为雷 · 中文版
初九：震来虩虩，后笑言哑哑，吉。
The line (Legge)
The first NINE, undivided, shows its subject, when the movement approaches, looking out and around with apprehension, and afterwards smiling and talking cheerfully. There will be good fortune.
Small Image commentary
'When the (time of) movement comes, he will be found looking out with apprehension:' - that feeling of dread leads to happiness. 'He yet smiles and talks cheerfully:' - the issue (of his dread) is that he adopts (proper) laws (for his course).
象曰：震来虩虩，恐致福也。笑言哑哑，后有则也。
In plain words
Thunder comes, and there is fright; afterwards laughter and talk: good fortune. The first line is the ruler of the hexagram: fear comes first, and then it learns caution. The Small Image says fear brings blessing, and the laughter afterwards comes from having found a rule.
Applying it to your situation
If you have just had a fright, this line suggests that being more careful afterwards is itself good fortune. What has this scare taught you?
Position
A solid (yang) line in the first place, which is a yang (odd) place, so it is in its proper place. Its partner is line 4; both are yang, so they do not respond.
If this line moves
With this line moving alone, Zhèn changes into Hexagram 16 Yù (Enthusiasm). The Jiaoshi Yilin verse for this change (Chinese): 焦氏易林·震之豫.
The hexagram
Hexagram 51 Zhèn (The Arousing Thunder). The Judgment: Zhen gives the intimation of ease and development. When (the time of) movement (which it indicates) comes, (the subject of the hexagram) will be found looking out with apprehension, and yet smiling and talking cheerfully. When the movement (like a crash of thunder) terrifies all within a hundred Li, he will be (like the sincere worshipper) who is not (startled into) letting go his ladle and (cup of) sacrificial spirits.
Next: Line 2
English text: James Legge, The Yi King (Sacred Books of the East, vol. 16, 1882), public domain, as transcribed by the Chinese Text Project. Chinese: the received text. Offered for study and reflection, not as prediction. Plain-English readings and position notes by this site.