Mass Effect 3 Citadel DLC stuck on loading screen

I bought the Citadel DLC last night for PC, and it downloaded and installed without a hitch. I received the email giving me the mission to go to the apartment on the Citadel, but when I dock and select "Personal Apartment", I get stuck in an endless loading screen with no option other than manually closing out of the game. I have tried to uninstall and reinstall the game, and I tried to repair from within Origin. I was using a mod (only for single player) to make the in game HUD larger on my 4k monitor, but I even disabled that and it still isn't working. Hopefully I didn't just spend $15 on an unplayable DLC. I don't know what else to try... any suggestions?