You could try reclamation yards if you're looking for something older and of a period. You could get a big chunky piece of wood. You could try tiles.

If you really don't like it and don't plan to use it but can't afford to remove it at the moment but will in the future, then you could paint it all the same colour as the wall. It's a very strong contrast to its surroundings at the moment. If you painted the wall a stronger colour then it would have a similar effect of reducing it's visual impact.

You have lots of choices.

To help you decide then you might want to ask yourself what it is at the moment that you don't like about it. To help us help you then we would need to know the answer to that question and why you can't remove it. If you use it or not. What style of room are you looking to create. Does it have a period style at the moment that you want to protect - I'm assuming not because it looks very modern.

I would choose a white or black surround in a plain fairly modern style - painted wooden are cheapest. There will be a space between the black insert and the surround, you could paint this the same colour as the walls, or tile the space for a more period look. A mirror (maybe round?) above the surround may help it look more planned.

Does your sofar face the fireplace? Could it?

*sofa

I'd make a 'fake' cast iron surround out of MDF and tile it with tiles. It's really not that difficult. If you stick a handful of sand in with your black paint it dries with a rough texture and looks a bit more like cast iron. Give it a really light dusting of a light grey / silver spray paint and it will gleam like iron.

I made the insert and fire surround to go round this disused fireplace and then we filled it with logs, but you've already got a fire, so even better.

If you then mask up your wall a foot or so either side of your fireplace and paint it the same colour as your sofa, it will really tie in well with the room .

Loving the tiles all the way up, great.

For me it is the ceiling to floor tiled wall that can transform this fireplace, like on the pictures above. f the wall was to stay as it is, I'd change the fireplace hearth surround to a more compact one as it seems to take too much space as it is at the moment. I think that grey fireplace will work better than black here. Just an idea.

Looking good! Can you perhaps share a photo showing more of the room?

I'm also curious where you've placed the TV.

Yes. Looking good.

And nice selfie! :)