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.
Fear and anxiety are part of life. You may feel anxious before you take a test or walk down a dark street. This kind of anxiety is useful - it can make you more alert or careful. It usually ends soon after you are out of the situation that caused it.