Action cures fear. The more you do, the less you fear. Don’t spend time thinking or overthinking about a worst-case scenario of something that has not happened and is not likely to happen.
If there are major consequences to your actions, take the time to think about the best way to approach the situation. Be serious and focused, do your research, read, talk with experts, get advice. But eventually, you have to make a decision with the information at hand. At that point, give yourself grace no matter the outcome. You did everything you could and were thoughtful in your approach.
If there are NOT major consequences to your decision, stop wasting time worrying about it. Time spent worrying is time taken away from enjoying life.