Back up both the "wallet.dat" and the "Wallet copy.dat" somewhere else so you have 1 or 2 extra copies of them before you do anything else. Also, backup any wallet.dat stored in here:
~/Library/Application Support/Bitcoin/
(see
https://en.bitcoin.it/wiki/Data_directory#Mac )
Make sure you have 2 backups of each - better to be safe.
The next step will be to figure out what happened exactly.
1.There isn't an external drive on this MacBook, is there?
2. Also, can you explain what you mean by "The wallet.dat file is still present but the wallet doesnt read the content of it as it looks like."
3. Do you know how those two files got on the Mac Desktop? That is not where Bitcoin Core stores them without some user intervention.
Hello Bitcoin community,
I am totally new to Bitcoin and at the moment i am a bit shocked.

Recently I downloaded the Bitcoin Core wallet onto my macbook and installed/synchronised all.
Received some coins in that wallet and closed it.
Opened the wallet next day again, and.... it's gone. no more BTC, no more transaction, no more address, all empty.
The wallet.dat file is still present but the wallet doesnt read the content of it as it looks like.
I want my BTC to show up again.
Does anybody know how to put back a wallet.dat file in a Bitcoin Core wallet on a Macbook?
In my desktop there is now two files: wallet.dat and Wallet copy.dat?
How do I get this wallet to work again?
Help!!