Sounds like you're anxious, which will lead to a stressful experience no matter where you're seated. Airports tend to be large, crowded, confusing, and loud, with people constantly rushing around.

The best way to improve your travel experience is to find techniques that help relax you as much as possible.

If it's a short haul flight, save yourself some hassle and put the seat selection out of your mind. You can use the time you would be worrying about and changing your seat to improve on ways you self-calm in stressful environments.

If the flight is more than a couple of hours, I'd recommend switching to a window or aisle. The benefit of the aisle seat is you can occasionally stretch your legs in the aisle, and more importantly, you can leave your seat unimpeded. The window gives you something to lean on, as well as cool views, particularly during takeoff and landing. If you're a nervous flyer that might be a negative.

I find it helpful to remember that just because everyone else is in a rush, you don't have to be. You don't have to run to your terminal, you don't have to rush to the front of the boarding line. You don't need to be the first on or off the plane. You can get to the airport a tad early, to give yourself time to walk slowly and rest as you need it.

There's ample staff at just about every airport, if you don't know where to go or what to do, ask them. Same is true on the plane itself, the flight crew is available to assist you.

Enjoy your trip!