The Op makes a big mistake because mobile wallets are never going for long-term holding and most wallet providers may not tell you this but it's the truth. According to the research conducted by the Computer Science and Engineering - Michigan State University.
It shows that mobile wallets are deemed to face a lot of security threats of
(1) deanonymize users’ real identities, Bitcoin addresses, and transactions,
(2) introduce continuous unwanted Bitcoin spamming traffic towards victims
(3) launch Bitcoin fraud attacks to take advantage of Bitcoin wallet users
You find the pdf file
hereHacked is a serious problem in cryptocurrencies, cases of hacked private keys, hacked accounts on exchanges and many more make us to be alert, few days ago my Google metamask was also hacked and made me lose around $500 and the best thing is to create a wallet then we write private manually on paper, make sure there is no internet connection then we take a photo and save the data.
It is just like the saying "there's no smoke without fire" what you just said now is another human error that will lead wallet hack and I believe this is one of the reasons why your Metamask wallet was hacked.