On the side of the shower opening that will support the door, hold a jamb piece against the wall so that its lower end fits into the base track. Without moving the track, use a 4-foot level to adjust the jamb until it's plumb. Stick a pencil through the jamb's screw holes to mark the wall.
I was asked to answer, so I'll give this my best shot, please know that I do not have any specialized or trained medical knowledge, only practical experience from Ashtanga yoga and meditation. So, yes, walking does reduce anxiety. 1.
Exercise is easily one of the most powerful, healthy anxiety management tools available. Sleep, Eating Healthy, etc. Living a healthy lifestyle is also important. From sleep to nutrition to hydration, the healthier your body is the better it works, and the better it works the less you'll experience anxiety.