I wiped my muddy shoes on the living room carpet
Why would you deliberately get the floor dirty?
I was very tired when I walked in, so I did not think of that. I'm sorry. I'm really tired today
You were too tired to remember not to wipe mud on the carpet? It doesn't matter because you're not going to be too tired to clean it up.
No, I'm too tired to clean it. Just leave it. The carpet is so dirty that I couldn't believe the people who own the house. I felt guilty.
You should not feel guilty as long as you clean it up. It would be better if you cleaned it up tonight though so that it does not dry in the carpet.