[1.12.2] (Help needed) Selective Block Rendering

Hello wonderful modders!

So I have a query: I have a block, which has a default texture (like all blocks). I'm wondering what would be the best way to go about having its texture change to a 2nd texture when the block is being looked at (within a certain distance and when holding a specific item with a specific metadata), and have it change back to the original texture otherwise. I'd like this to apply to blocks within an imaginary circle on the screen (so, the block being directly looked at and a few around it, based on what would essentially be a 2d-screen-to-3d-world raycast). I don't know if this should be done with a TileEntity and/or TESR, or blockstates (idrk how blockstates work). Help would be greatly appreciated.