does saying Tehilim without understanding what the word mean help?
It is definitely better to understand what you are saying, but even if you don’t understand what you are saying it helps. Tehillim, Shemona Esrei and the other tefillos that were made by Anshei Kneses Hagedola, are packed with loads of deep secrets that even if we don’t know them, but H-shem does, and it has an effect. Yackov Aveinu told his children that there are two types of tefilloh (b’charbi ubkashti – like my sword and arrow) compared our tefillos to a sword. A sword, which is sharp and has weight to it and when it is put down on something it cuts it automatically. There is another type of tefiiloh called a sheshes, an arrow. An arrow will only hurt someone when it is shot with tremendous power, the kavana and feeling that put into the tefilloh is the arrow part. Therefore even if we say tehillim without knowing the meaning, it still has an effect.
Have a good Moed