I’m sorry to hear you had your id stolen. However, you shouldn’t confuse privacy with security.
Privacy can help by limiting the amount of information an attacker can gather about you online, however, it will not help you if your account on a website with information is hacked or leaked, that is really the domain of account security. Qubes will not help you with ID theft, if you give the information to the site anyway.
In your circumstance, deleting all non-essential accounts, particularly on sites that perhaps don’t appear so secure, and implementing 2FA is key, so that’s a good start. Another fundamental precept of account security is to use a good password manager, with a strong masterkey. This means every site has a different, random and strong password. Some good selections are Keepass/KeepassXC or Bitwarden. That way you can be sure that one account compromise is unlikely to lead to another.
Another thing that you can do, is where possible and legal, provide as little information, or false information, to those websites that ask for it. I would also suggest getting rid of your social media, or at least auditing it’s privacy settings and the identifying information that you have posted. Remember that even if your social media practices are good, your careless friends can ruin it and reveal almost as much info about you.
I would also make sure that you are using a modern operating system and browser with an adblocker (can’t beat Firefox with uBlock Origin on Qubes, Whonix or Fedora/Debian), with all the latest updates.
You should also ensure that your mobile phone account and voicemail has pin security enabled, and any other security options your provider allows to protect your account should be used, as this is a common target of ID theft.