That's the reason why government do not legalize cryptocurrency that easily due to some hacked exchanges and that's a serious issue.
You just need to become more careful and become responsible with your assets so that you will not become the next victim of those hackers. Criminals will not be completely eliminated so that using cryptocurrency is risky in some point. But in order to become confident in your assets, increase your security especially your bitcoin wallets and learn how to choose a reputable exchange where there's no history of getting hacked. Plus, choose an exchange that immediately fix the issue in their platform with an improved security so that you can become free from that insecurity that you are saying.