I disagree with the University of Washington's literacy project information because I feel like anxiety is an overstatement for trying to find a topic to research. I can see where the students are coming from but I would feel more overwhelmed and eventually I just pick a topic and run with it. One thing you might be able to do with your research anxiety would be to narrow your topics down to something that you enjoy and know a lot about.
It's always smart to pick a topic that you can relate to; this just makes the whole process so much smoother.
I do think that some people feel anxious about it. I have witnessed you write many papers that require great research, so I know that you write well and do not struggle nearly as much as many others do. I think the abilities of others when they are not as strong as yours causes anxiety.