The only way for you to lost your BTC is by phishing scams or the hackers stole your private key.
What kind of wallet do you use?
Web-based wallets are tend to be insecure due to how the private keys are stored on the cloud.
I'd suggest to get desktop wallet as you have more controls of your private key, just make sure your PC are clean from malware and junks.
If you're really serious about security you can get hardware based wallet like Trezor or paper wallet, that should be enough.
This is true, other than that, you won't be hacked unless you have a famous name in the community or you are known to have so many BTC, but if you are in the cold storage or wallet that is really safe, for example electrum, then they can't hacked it easily bro. What I mean is this is one of the main features of BTC "SECURITY", if someone can break the system, then this will be a chaos and everyone will be selling all their coins.
Firsts things first is that we must know how cryptography is so safe that there is no technology today that can break the system, or hacked the system.
And yes, Trezor and paper is one of the safest, just have a vault in your house to have extra security, especially if you have 10 BTC or up.
IF you can't afford a cold storage then buy some Anti-Virus, because it is another layer of protection from harmful sites and phishing sites. ALways backed up your seeds or write it up on paper just to be sure. Your computer is a machine and you should be responsible on whatever may happen on your computer. Treat it more than your wallet and never ever trust anyone to have your seeds.
Don't trust online drives (Google, microsoft). The government might be watching you (they have eagleeye or prism project) and its dangerous to have all your files online) Write it down on paper and provide a copies and lock it on a vault at home. The best security is your own home.