How do I stop my boyfriend from hacking my phone and devices?

One more step in addition to Idris' excellent suggestions, in case his already accessed the devices, and installed something:

6. Restore the device to Factory Condition, to remove any installed Software. Then install your Apps one by one so you know exactly what is on each device.

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

1. Change your Apple ID passcode to something he will not be able to guess.
2. Set up Two Factor authentication on your Apple ID.
3. Change the lock codes on all of your devices to something he won't be likely to guess.
4. Never allow him access to your devices when they are unlocked. For any reason.
5. Find a boyfriend who respects your privacy. The lack of respect he his showing you indicates a relationship headed for an unpleasant end.

Two-factor authentication for Apple ID - Apple Support

The iPhone and iPod are much harder to install things like keyloggers on. It is more likely, in those cases, that he has guessed your Apple ID password. That would give him lots of information.

Restore your phone (and iPod) to factory state, make the changes we recommended. Your iPhone and iPod should be protected.

If your computer is a Mac, post in the Mac forums for additional assistance. But, I'd start by running Malwarebytes. It's free to run and was developed by a long time forum member.

Malwarebytes for Mac — Mac Antivirus Replacement | Malwarebytes

It's none of my business but, I hope you're also reaching out to resources for people in abusive relationships. That's what this is. I wish you all the best in working this out.

Be safe.

Yes, a very important step!

IdrisSeabright wrote:

Yes, a very important step!

😉