My counter question is, does it really matter?
You are you, brought back from the dead. Hopefully you died from being frozen, otherwise your body won't be very usable, even after reanimation.
With a bit of luck, you are the only you in existence, if you are not, then there is your answer. You aren't really you, because there is more than one of you.
But back to my original statement, does it matter? If somehow someone or something is abusing your past or memories to get you to do their bidding, then yes, you should ask the question of your memories are real. In any other case, you can go about living your continued life however you like. In essence, you are you. You are the one that exists in that moment in time, with the memories you have. Whether the memories are real or not, or the body is, does not matter, it can't be changed anyway. It will practically change nothing in your life apart from sending you into an unnecessary existential crisis.
The only way you will find out is by asking whomever resurrected you, and hope you can trust them. But I wouldn't do that, unless you have no other choice.