It felt like I was really out of shape. I had not run or did much exercise for the past month or two. My legs were starting to cramp up at around 20km, and had to struggle to finish the last km or so. I wasn't really out if breath though, so I think I just need more muscle endurance training. The hot shower afterwards felt great and it feels amazing to run again.

Not at all, don't apologize. Your post is very well written; I just read it, great job!