20 pounds in 6 weeks? That is fantastical! Of that time, how long have you been stalled? It is probably a normal process that is common after a really good loss like you have had. When we lose fast, our bodies need time to adjust to the losses and will slow, or sometimes stop for just a little bit. If you haven't done so yet, try taking body measurements. Just because the scale isn't moving doesn't mean that you aren't losing inches.