Note: "if you ever experience a situation like that again" is not a sentence - it is a phrase. A complete sentence must have a subject and a predicate (the predicate contains the verb). Usually, when you begin a sentence with "If ..", you must complete it with a sentence beginning with "then". Example: "If it rains tomorrow, then I will not go to the park." Of course, most people do not include the word "then", so the sentence becomes, "If it rains tomorrow, I will not go to the park." This is also grammatically correct.

Hello Pelin, No, it is not ok. It is incomplete. There is an "if", but nothing following. Correct could be: "If you ever experience a situation like that again, call me right away."