My work approached me a couple weeks ago about a position they are creating that they want me to…

My work approached me a couple weeks ago about a position they are creating that they want me to step into. I said I was interested and didn't expect to hear more about it until I got back from my leave. I've got three working days left before my leave starts and my supervisor told me they will be interviewing me for the position on Monday. Now I'm panicking! Honestly, I've checked out a little bit and my pregnancy brain is at its max right now. I'm not mentally prepared to do this! Lol any advice?