Why did you pitch more yeast? After 3 days it's at 1.020 that's where it should be. It doesn't mean fermentation isn't still going on.
Bubbling and fermetnation are NOT the same thing. airlocks and blowoffs are simply vents, valves to relieve the pressure and keep you from having beer on your ceiling. They are NOT magic fermentation gauges.
Airlock activity is irrevelent. Just gravity points on a hydrometer.
Airlock bubbling (or lack) and fermentation are not the same thing. You have to separate that from your mindset. Airlock bubbling can be a sign of fermentation, but not a good one, because the airlock will often blip or not blip for various other reasons...so it is a tenuous connection at best.
Fermentation is not always "dynamic," just because you don't SEE anything happening, doesn't mean that any-thing's wrong,, and also doesn't mean that the yeast are still not working diligently away, doing what they've been doing for over 4,000 years.
Don't do ANYTHING else to your beer for another 2 or 3 weeks. Don't rack it, don't look at it. Just leave it alone. Everything is ans WAS fine. You went to try to fix something that wasn't even broken.
You did good by taking a hydro reading...but it didn't show that you needed to DO anything...just that the beer was happily fermenting away REGARDLESS of what the airlock was doing.