I feel this!
For me it's that I promise myself at the end of the day I'll work on mine only to find myself completely exhausted and instead go down a Youtube rabbit hole until I pass out. It seems worse when I hit a wall in the game making process that's hard to break, like spending hours figuring out how to resolve something and feeling that you've spent so much time on something "not productive."
Today I might need to take some time for a break too. I got a lot of work stuff and the kids tonight and I should probably regroup a little. I also had that same issue with Gifs and even regular screenshots! Maybe the upload size limit goes for not just posts but the collective amount of posts on a single thread? My last one I had to just add a link to my image on Imgur.
Good luck with keeping the momentum! It's looking fun! :D