p.s. hopefully i'll be able to get a wink of sleep tonight
Are you running Windows? If so make sure you have things like Windows Defender and Firewall running to help protect yourself against malware. (otherwise, pick any decent supported Firewall and malware protection software for whichever O/S you're running)
Also in Windows, consider enabling Bitlocker drive encryption (Again, for other devices, consider some other drive encryption mechanism)
Consider hosting files in a secure cloud drive instead of having everything stored locally, and make sure that your account for those are protected with Multi-Factor Authentication (i.e. Password and Authenticator). For example, using OneDrive or Google Drive -- https://support.google.com/drive/answer/141702
Make sure you use strong passwords for your accounts which consist of more than one word, use mixed-case letters, numbers and non-alphanumeric characters. Always use multi-factor authentication wherever it's available. If you have lots of different accounts on different sites, then you could consider using a Digital password vault to help you manage your passwords in one place and auto-generate strong passwords for individual sites.
If you're going to be connecting to public wi-fi networks then consider paying for a good quality secure VPN service like NordVPN too
Lastly, just learn to be vigilant. Most people who suffer security breaches were victims of social engineering - for example, they handed over their own personal details over the telephone to someone impersonating a bank or private company, or they fell for a "phishing" scam in an e-mail, or they downloaded and ran a dodgy file from a dodgy website on the internet somewhere. The best thing anyone can do to protect themselves is just to keep your wits about you and never be complacent about your security or privacy. (remember that someone who has enough of your personal data can potentially "steal" your identity, and impersonate you to get around your security; so if you make it hard for people to get your personal data, you make it hard for them to impersonate you)