Metamask is the most used wallet that has been in use for both Ethereum coins and the Smart BCH. And it's kind of difficult to navigate and protect the funds. I have listed few practices in my article to show you how to secure the funds. Do give it a read :) Check out the article: https://read.cash/@esmeesmith/how-to-secure-smartbch-funds-in-metamask-wallet-59b6a0c6