So, I automated this using PipeDream some of my own code.
I started off by creating a trigger that automatically runs the code every 5 minutes.
After that, I created a method that refreshes my token every hour so it doesn't expire (which takes around 2 hours), and you can find it at get_auth_token.js.
Then I used some Python because it was a lot easier to work with for this, it gets the cat image, saves it to a temp file which gets deleted later, uploads the image to Twitter and gets the media id from that, then it creates a new tweet with the image and some text! You can find that code here: get_cat_and_post.py.
I also needed consumer keys, so I created a quick get_consumer_keys.py for that. It's not great, but does the job. After you do that you can paste in the keys in the other python file and it should work!
Happy catting!