All my photos and videos from my home computer are on my phone (taking up way too much space). I can't delete the videos from my phone. I want them on the computer, but not on my phone. Help!

All my photos and videos from my home computer are on my phone (thus taking up way too much space). I can't delete many the videos from my phone. I want them on the computer, but not on my phone. Help!

I do use iCloud (I like the pix from my phone to automatically link to my computer, but not vice versa). I think we must have changed a setting, because these videos weren't always on my phone. I only like to keep a few video clips on my phone because otherwise there is too much space taken up on icloud without purchasing more.

My back up is old because there is too much on my phone to back up now. I need to delete the videos (or unsync them) before backing up and moving forward. I do have ALL photos on my computer, so am fine deleting from phone (but there are contacts and other things on my phone that may not be backed up so I prefer not to swipe my phone clean or use an old back up unless I have to).

Thanks!!!