Currently I am reviewing all the embarrassing parts of the interview, pacing, and repeating "You're an idiot" over and over to myself.
You probably didn't get the job from your description, but don't sweat it. My career has been in management and management consulting, I've given and taken many, many interviews. When I graduated from Michigan with my MBA, I did get my dream job in management consulting and I had other good offers. However, I also had interviews where I just didn't connect with the interviewer or I thought I did well and yet got nothing back. It's a crap shoot. You, your interviewer(s) and the job have to line up at the same time or it doesn't work. Practice can increase your odds, but there is no perfect system.
I also had one interview with Gemini Consulting which was the worst interview I ever did in my life. I was just off that day. It was pretty similar to yours, I just couldn't be clear and articulate and I kept forgetting things and going back to them. At the end of the interview, I just told the interviewer I know I didn't get the job, I said sorry, but I just can't speak clearly today. He was polite, but I still didn't get a callback. LOL. Didn't expect one. But I got multiple better jobs. And missed on other better jobs. Just work and improve and you'll find the right fit.