I Broke Solitude in Skyrim and Need Help

I’ve been playing Skyrim PC recently, and was working through the Civil War questline with the Stormcloaks. I had a bounty of 1,059 gold when I completed the Fort Greenwall quest. I returned to Galmar Stone-Fist and started the Battle for Solitude quest.

On my way to Solitude, I was stopped by a guard and paid off my bounty, resulting in it loading with me outside Castle Dour. Due to that, the quest progressed to where I needed to kill General Tulius inside.

A while later, when attempting to return to Solitude, it didn’t show up on my map, so I walked and when I attempted to enter the city, it spawned Ulfric and several Stormcloaks. Ulfric gave a battle speech to pep the troops on to attack the city.

I assumed that I would just have to go through the quest again, and went up to the city, but when I attempted to open the door, I received this message onscreen: "You must help the soldiers defend the city before you can enter."

I waited to see if I could bypass this. I researched online to see if I could complete the quest using commands, but that also came up bust.

I save over my previous save games to conserve space, and so I can’t go back to a previous save to retry this. Please help me figure out how to fix this, or uncover my autosaves to go back and redo this.