Did shermans march help end the civil war?

Yes.

It vividly demonstrated to all parties that the Confederacy was too weak to survive.

The recent good harvest in this rich farm country enabled Sherman's army to live off the land, and ignore the persistent dangers to their supply-line.

What they couldn't eat, they burned, so the Confederate armies were soon on short rations.

And the civilian population were so demoralised that they actually urged the troops to cross the river and ravage their sister Confederate state of South Carolina, which had started the war.

Sherman was, of course, happy to do just this.