First, so sorry to hear that, and hopefully, you are really tough to face this incident.
Second, you own big amount of BTC, 3,5BTC, and you don't know about storing it on the hardware? Sorry, not to blame you, but this is am kind of very important lesson.
Whether this story is really real or not, but this can be a lesson for all related to the safety of storing BTC. Before having BTC, basics like this should be understood, related to volatility and security of how to store BTC safely. In addition, the most basic thing is about the new information that we must check again and again, as faced by the OP, namely the number of phishing that causes loss of assets.

yeah there is nothing to be able to be done to recover the funds because it has been lost exactly. This is not the first, not the first case and this happens very often. theft and fraud in the crypto world also very often occur with models that are often almost similar. Should this always be a lesson for everyone? Care must be taken in this matter, no matter how assets.