Eat two bananas for breakfast. This should help your potassium. Although if you are already raw vegan, you are probably doing that or something similar already.
Are you sure it is 2.0? My understanding is that people die well before it reaches that.
My potassium was 3.6 before starting my water fast. That is risky because while still barely within range, I had no margin and was doing the fast unsupervised.