It is not easy to make that decision to go back to school! I would say that it was very nerve racking and weird to be back in school especially if you would start at a new university. For me the fear about being back in school easily dissipated once I got started with classes. I found myself able to converse with my professors alot easier and most of them were really intrigued by my story and wanted to help in any way they could. Taking upper division bio classes, I would say most of my classmates were only a year younger than me or slightly older which made for easy conversations. The most common question you get is "what major are you studying?" which I would just laugh and say I'm taking classes for fun. For me I was planning on applying last year, but after a long look at myself and my application I decided against applying and immediately started taking summer classes at my local state university. I didn't figure out my post bacc until 1 week into summer session, so that was kinda hectic. The hardest part for me was the scramble to get into classes to start each semester, but you just gotta persevere and crash every course!
I don't know what you hope to gain from your post bacc, but for me I treated it as a chance to show that I could be an A+ student. It wasn't a year wasted since I developed study strategies and time management skills that I would have otherwise not had. Also the fact that it brought my gpa above a 3.0 and got me 3 interviews so far. As my colleague mentioned, you still have to do some research and look at your current application to determine how you can maximize the effects of your post bacc. For me the biggest weakness in my application was my gpa and that had to get fixed, I was certain that I was not going to get any notice if my gpa was below a 3.0. This made it easier for me to commit to a full year of post bacc courses.
Be sure to take advantage of other opportunities you might receive during your post bacc. I was able to befriend one of my professors and work in his research lab, an opportunity I would have likely not have been able to actualize if I didn't go back to school.
Delaying your application cycle one year is perfectly fine. Use it to pursue extracirriculars that excite you and really beef up your application!