I felt the same way as you, but eventually I started flying on Expert. Here are my tips:
Do your first few Expert Server flights between two airports without ATC, just to prepare yourself.
Then, when you’re ready, fly to/from an airport Which has ATC but is not busy (For example I flew into KALB instead of KJFK). If you make a mistake, contact the controller and ask what you did wrong.
After you are comfortable flying into “quiet” airports try flying into/out of a busy airport (not the featured one) with ATC, for example (last week) LSGG instead of LIRF. Follow ALL ATC instructions and read tutorials to prepare yourself for any commands they might give you.
Next, fly into/from the featured airport on the ATC schedule. This will be very busy, so don’t send duplicate requests or spam the frequency. Follow ALL ATC instructions. If they tell you to go around, go around.
Finally, once you are ready, fly into or out of the FNF airport. This will be VERY BUSY but if you follow instructions and have read all the tutorials you will be fine.
Hope this helps :)