How strong is strong enough
Sixteen characters with letters, numbers, and symbols is comfortably beyond what brute-force attacks can reach. Use a different password for your bank, remittance app, and email, and keep them in a password manager rather than a notebook.
For OFWs especially
Your email is the master key to GCash, bank, DMW, and OWWA accounts. Change that one first, and turn on two-factor authentication where it's offered.