Hello haley1jill,
We noted that you're having issues viewing photos from earlier in the year in your Messages conversation, and we'd be happy to help out with that.
If you tap the contact's name at the top of the Messages conversation, scroll down to Photos, and tap See All, do the expected photos show up there? It may take a bit to load them all if you have a lot.
Also check to see if your Messages app shows "Downloading Messages from iCloud" at the bottom of the list of conversation threads. If so, connect your device to power and Wi-Fi, and it should help proceed with that.
If you're using Messages in iCloud, try turning this off, wait a few moments, and then re-enable it. Then, keep your device connected to both power and Wi-Fi. This page has details on this if needed: Use Messages in iCloud
Take care.