Hello idontknowwhatnametouse,
Thank you for using Apple Support Communities. If your messages are not appearing on your iPhone or across all your devices, we can try some steps to see if we can get this issue sorted out. First, make sure that you've set up iCloud for Messages correctly. This feature allows your messages to sync across all your compatible devices that are using the same Apple ID: Set up iCloud for Messages on all your devices - Apple Support
On your iPhone:
1.) On your iPhone, iPad, or iPod touch, go to Settings > [your name] > iCloud.
2.) Do one of the following:
-iOS 16, iPadOS 16, or later: Tap Show All, tap Messages, then turn on Sync this [device].
-iOS 15, iPadOS 15, or earlier: Turn on Messages: Any messages currently stored in iCloud are now accessible on your device, and any new messages you receive on your device will be stored in iCloud.
3.) To make sure you can see your messages on all your devices, also check the following:
-iMessage account: On your iPhone, iPad, or iPod touch, go to Settings > Messages > Send & Receive. Make sure that you’re signed in to iMessage with the same Apple ID. You can choose which email addresses and phone numbers you want to send and receive messages from on each device.
-Text message forwarding: If you want to receive SMS and MMS messages on all your devices, go to Settings > Messages > Text Message Forwarding on your iPhone. Turn on text message forwarding for each device. For more information, see the Apple Support article How to forward SMS/MMS text messages from your iPhone to your iPad, iPod touch or Mac.
4.) To see messages stored in iCloud, open the Messages app.
On Mac:
1.) In the Messages app on your Mac, do one of the following:
-macOS Ventura: Choose Messages > Settings, click iMessage, then select Enable Messages in iCloud.
-macOS 12 or earlier: Choose Messages > Preferences, click iMessage, then select Enable Messages in iCloud.
2.) Select which email addresses and phone numbers you want to send and receive messages from on your Mac. Any messages currently stored in iCloud are now accessible on your Mac, and any new messages you receive on your Mac will be stored in iCloud. If you want to see SMS and MMS messages on your Mac, see the Apple Support article How to forward SMS/MMS text messages from your iPhone to your iPad, iPod touch or Mac.
3.) To see Messages stored in iCloud, open the Messages app.
Other possible steps you can try is to make sure all your devices are fully updated. This usually helps resolve various issues and also helps with performance:
1.) Update iPhone
2.) Update Mac
Feel free to keep us posted on your results. Thank you for using Apple Support Communities.