Why are my videos taking so long to download?

I put together an iMovie and before I could share it my phone decided that it wanted to download the videos I used to iCloud. At first, I had no problem with this. I would just wait and then share the video later. But 3 days later and I’m still waiting for the videos to “download to iCloud”. I tried to play it to screenrecord it and share it that way but I can’t play it either. Someone please help!