First of all, honesty is the most important thing. You must tell your boyfriend that you leaked his privacy and admit your mistake. You must sincerely apologize to him and promise that this will not happen again. This is the key to rebuilding trust and restoring relations.
Secondly, you need to respect his feelings. Boyfriends may feel angry, depressed and disappointed. You must respect his feelings and give him enough time and space to deal with his emotions. Don't try to force the relationship back, it may make the situation worse.
Finally, you need to take measures to prevent similar things from happening again. You can consider using passwords to protect your devices and accounts, and to limit how you can share your privacy. You can also consider seeking professional help, such as a counselor or therapist, to help you deal with the emotional impact of privacy disclosure.
In a word, privacy leakage is a very serious matter, which may cause lasting damage to your relationship. However, if you are honest and respectful and take measures to prevent it from happening again, you can try to save your boyfriend's heart and rebuild your relationship.