Overwhelmed by Work Anxiety

One of the best things I think you can do is to isolate a task. For instance let's say you need to read these articles and write a paper on each. What I would do it pull up one article and just one, have nothing else in my line of sight then read it. It helps to I keep on one task instead of focusing on the fact that you have several. Sometimes making a list can help but they overwhelm me.

For me, the main thing that helped was not expecting myself to immediately be at 100%. It was to accept that my capacity could fluctuate on a day-to-day or even hour-to-hour basis, and that my job performance or "productivity" didn't have to be perfect for me to still be worthy of the job. it sounds like you have a tendency towards perfectionism, and that combined with the pressure of your new job is causing this overwhelming feeling of anxiety and hopelessness, even though you enjoy your colleagues.