If you're having issues throwing larger images into your post, I wanted to mention that you can embed those images in your post instead! You'll have to upload your images to a third-party site for now, unfortunately, but this is kinda just a workaround for the current times.
Here's the HTML of what I've been using to make a single image look nice + make the image clickable for folks who want to zoom in a bit. Put this all in the body of your post, don't bother with Cohost's default headline (I do this because the headline has an awkward amount of space between it and the image, and I don't like it).
### (header here)
<a href="image link here">
<img src="image link here" style="margin: 0px auto">
</a>
Alternatively, for multiple images, I would recommend using nex3's image grid generator!
Hope this is helpful. <3