Advice on Overtraining and Rest Days

So I just completed the first week of FB strong a few days ago, and I felt really great the whole week so I added on extra 15-20 minute workouts on top of the scheduled workouts, putting me working out around 50-60 minutes a day. I only took one active rest day within the 7 day period and it was a 2 mi walk in the middle of the week. (I skipped the scheduled active recovery days and did full length workouts on those days because I felt strong and wasn't really sore, bad decision, I know.)

So in this workout period (week 1 of Strong + separate workouts and a few extra workout days) I ended up working out 12 days, and taking 3 active rest days sprinkled in between them.

However, I know I severely over trained because I am incredibly sore all over, fatigued and even a fairly light stretching routine like the active recovery days in Strong seem difficult right now. I'm going to try to tone it down quite a bit after this and take 2-3 rest days a week (with one complete rest day) and maybe start Burn or Abs 2 instead of finishing up Strong. (Don't feel like heavy strength training right now.)

My question with all this is: I felt fine through the whole 12 days, which is why I kept going because I didn't want to just sit still when I felt like I could workout. How do I know when I need to take rest days if the soreness doesn't catch up to me until 2 or 3 days later?

Also, is it better to take rest days between workouts, (i.e workout 2 days, a rest day, workout 2 more days, rest day) or to take all the rest days for the week at one time, sort of how it's laid out in strong (at the end of the week?)

Sorry this got so long, I'm just trying to figure all this out so I can avoid crashing again. Any advice or tips would be greatly appreciated!

Thanks FB community!

Edited