suffering from, preventing from 中的 from 的意思？

"from" is a preposition. It doesn't carry any meanings but you must use it in your examples.

You need to use prepositions after some other verbs, say,
- He decided (verb) "to" tell the truth.
- They want (verb) "to" buy a new house.
- She insisted (verb) "on" seeing it.
- The test consists (verb) "of" 4 parts.