The kind speaker introduced me to the audience. I tried to stay calm. I felt nervous walking up to the stage.
In which two ways can the sentences be correctly combined?

The kind speaker introduced me to the audience, but I tried to stay calm, I felt nervous walking up to the stage.
After the kind speaker introduced me to the audience, I tried to stay calm, but I felt nervous walking up to the stage.
Once the kind speaker introduced me to the audience; I tried to stay calm although I felt nervous walking up to the stage.
The kind speaker introduced me to the audience, and I tried to stay calm as I felt nervous walking up to the stage.
The kind speaker introduced me to the audience but I tried to stay calm; and I felt nervous walking up to the stage.