Welcome to the Retail World of Day Trading !
You are undergoing Market 101 course which everyone including Jesse livermore to Jhunjhunwala had undergone.
This happens to every new trader who ventures in to the market for the first time.One could avoid this by following the precaution to some extent:
A) not trading stocks based on news and brokerage tips.
B) never chase the price.
C) follow some technical analysis before coming to conclusion.
D) lastly market factors good / bad news well in advance.So one should not enter trades after events or results.