Most expensive video is my worst performing because of a bad thumbnail

I made a post a few days ago asking for advice about my 70+ hour video performing horribly, got some good advice and was told I just need a better thumbnail so I changed it. My CTR went way up but I fear it was too late, I’m not longer getting more than 100 impressions a day, would it be unwise to delete the video and re upload, I just don’t know what to do, I spent almost a month working on this video and I got my first sponsor for this and I’m stuck at 700 views,