Sorry for your loss. So after reading the story I realized that someone targeted you because he didn't transfer the funds even after looking into your $7k wallet. He knew that you have a large amount of funds and that you will use this wallet again to make transactions.
It's quite possible. Sometimes it's those closest to us that we forget to look into or don't suspect initially. I would like to ask OP who else close to him/her has access to the computer/phone they were using? Who knew about the money they had and were expecting to receive in the wallet that got emptied?
It is also possible that your computer was already under the control of the hacker, so that he could see all your activities.
I think that if the hacker had prior access to the wallet, he would have emptied it when he saw the $7k in it. Unless, of course, the person knew it's only a matter of time before something more vulnerable gets deposited there. The question OP needs to ask themselves is how could they have known, and who knew of the upcoming transaction?