No, I’m afraid the phrase is not a proper sentence and it is very hard to understand.
If I understand your intended meaning (and it’s possible I do not — maybe someone who knows better Chinese will help), a better way to put it would be: “Are you asking me who it is that I remember the best?” (Alternatives would be “Are you asking me who the person I remember the best is?” or “Are you asking me who(m ) I remember the best?”)
For one thing, it’s not a full sentence, since there’s no independent clause. There is an if-clause with no then-clause. There is also a clause that is subordinate to the if-clause. The subordinate clause, introduced by “who”, is incorrect because it uses inversion.