difference between thought and opinion

I am working on the podcast #188 homework. My current painful thought: “I don’t know if I can rely on myself to follow through on my goals.” The questions ask me to separate out what part is not factual, and what is my opinion, in this thought. Here is where I am getting confused about the terms and concepts; isn’t a thought by definition “not factual” and “my opinion”? Help! I want to understand this! thank you.