Imovie Download

Hello. I am trying to save my Imovie that I made on my phone to my photos so then I can download it to my computer. IT says there is not enough space on my phone to download my movie. I deleted a bunch of apps to get the space I needed and it still wouldn't save. It is about 50 min of video so about 6.2GB is needed and it says I have 4.5 available. When I go to my storage alot of space is being taken up by my photos which I should have stored in the cloud. My question is why are my photos taking up all the space on my phone if I have paid for cloud storage? And how do I get around this so I can download my movie then delete the videos from my phone. THanks!