I can't share a video from my Photos

Last night I was recording videos with my iPhone 12 Camera app at a concert. Midway through one of the videos, I got a pop-up that either said my iCloud storage was full or my iPhone storage was full (I can't remember which). It stopped the video and that was that. I checked later and found that neither are full (140GB left on iCloud, 6GB left on iPhone), but I ran into a problem when trying to share that video specifically. No matter which app I use (Snapchat, Instagram, Messages) I cannot send or upload the video to anyone or any story, it never finishes uploading and always runs into some error. I do not want to lose the video, but I want to be able to share it with people. Why is this happening, and how can I fix it?