"end" vs "get over"

English as a Second Language English Vocabulary, Grammar and Idioms
1

“This kind of pain lasts much longer and it does not get over in 15-20 days.”

  1. Will there be any change in meaning if I use “end” in place of “get over”?

  2. Can I use only “over”? If not why?

2

  1. Yes, there is, I think. ‘get over’ has a sense of ‘recover’ whereas ‘end’ could mean ‘stop’ but I feel it’s awkward to use ‘end’ here.

  2. No, you can’t. Because ‘over’ can’t stand here alone as a verb which the sentence needs.

3

This is a very ungrammatical sentence, because pain does not get over. The person gets over the pain.

The most normal ways to state the matter would be:

“This kind of pain lasts much longer and does not end for 15-20 days.”
“This kind of pain lasts much longer and does not stop for 15-20 days.”

“This kind of pain lasts much longer and [color=red]the patient does not get over [color=red]it for 15-20 days.”