You are not stupid. Please never think of yourself as stupid. These are just things in life we learn from so we know later to never make that mistake again. You must first fail in order to succeed. There are horrible people in this world and there will always be. One mistake or accident should not ruin that for you. Its not 100% your fault so you should not think that way.

Aniiiiiways~ I truly hope that things will turn about one day.. and hey who knows perhaps that person will in turn get scammed in the future as well.