Hem in
Definition 1 of 2
Pro Tip 1/3Physical Barrier
Used when someone is physically trapped by objects or people. 
Tourists in the narrow alley were hemmed in by vendors.
Pro Tip 2/3Feeling Trapped
Can express feeling overwhelmed or without escape. 
At the packed concert, I felt hemmed in and needed fresh air.
Pro Tip 3/3No Direct Route
Implies having to take a different path due to being surrounded. 
We were hemmed in by the parade and had to circle back.