He is being struck by remorse

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. He is being struck by remorse.
  2. He was struck by remorse.
    Which one is correct?
2

#1 is grammatical but does not seem terribly likely in practice.

#2 is OK.

3

Both are possible, but the first would usually be recast:
He is struck by remorse.
Using ‘being’ would be very unusual because it is not usually necessary to focus on the act as it takes place. (The only usage would be in something like ‘This picture shows someone who is being struck with remorse’)

The first is present tense and the second is past tense.