Correct?

I met him at the party. We had a lot of fun. He got injured two weeks after. He is still in hospital but I can’t believe it.
First two sentences are correct. The third cannot start with ‘And’ (if you wish to combine two short sentences, join the first two.)
The last two short sentences should be separated with a period or joined with a conjunction (such as ‘but’). The final word, “this” do

Atleast the use of 'two weeks after' is correct, right?

AnonymousAtleast the use of 'two weeks after' is correct, right?

Yes, because it refers back to the party. Good catch.

Anonymoushe got injured two weeks after.

'two weeks later' is much more idiomatic.

CJ

CalifJim'two weeks later' is much more idiomatic.

That's more natural.

Do you want to say 'two weeks earlier' is much more natural than 'two weeks before' with the same situation?

AnonymousDo you want to say 'two weeks earlier' is much more natural than 'two weeks before' with the same situation?

Since the question hasn't come up, I don't actually want to say anything about it. The thought hadn't crossed my mind. Nevertheless, since you ask, I don't think a comparison between 'earlier' and 'before' shows as much difference as b