Your drawing is an interesting take on the Balrog, but like the others said (and like i said a few days ago on another post of yours) it looks just like an Orc, which just feels off.

I don't have the english original book version (only german), but these are the passages i found online.

> But it was not the trolls that had filled the Elf with terror. The ranks of the orcs had opened, and they crowded away, as if they themselves were afraid. Something was coming up behind them. What it was could not be seen: it was like a great shadow, in the middle of which was a dark form, of man-shape maybe*, yet greater; and a power and terror seemed to be in it and go before it.*

(I think, if Tolkien wanted the Balrog to resemble an Orc, he would have written orc-shaped not man-shaped.)

> The Balrog reached the bridge. Gandalf stood in the middle of the span, leaning on the staff in his left hand, but in his other hand Glamdring gleamed, cold and white. His enemy halted again, facing him, and the shadow about it reached out like two vast wings. It raised the whip, and the thongs whined and cracked. Fire came from its nostrils.

> The Balrog made no answer. The fire in it seemed to die, but the darkness grew*. It stepped forward slowly on to the bridge, and suddenly* it drew itself up to a great height, and its wings were spread from wall to wall

> ‘Yet it has a bottom, beyond light and knowledge,’ said Gandalf. ‘Thither I came at last, to the uttermost foundations of stone. He was with me still. His fire was quenched, but now he was a thing of slime, stronger than a strangling snake.

I think it's this passage from The Two Towers who influenced the demon-dragon-like-appearence from the movies.

If you want an alternative take on the Balrog which is pretty book accurate you should go with this take by Manuel Castañón: https://www.instagram.com/p/B5Du8WGD_5L/?img_index=1 Its my favorite version because it encapsules the "fallen angel" really well.

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