You have to use "a whole bunch of sprites" to do something like this.
I've done things like this in the past, and I used an array to track the tile types and health... and used that same array to display the tiles on screen so I could basically have an unlimited map size with only the number of tiles that are on screen at once displayed - the rest were "non-existent" if they weren't actually on-screen.
I'm not sure how tilemap actually works since I've never used it - but I made my destructible tile terrain (as well as other types) in Construct Classic a few years ago.
It's not going to be the easiest task to achieve, unless someone else here has a really elegant and easy method to it.
~Sol