google play uses wrong account for in-app purchases
I found that I had a similar problem. What I did was completely reset my device, and then only associate my business account with it. That way my Gmail App is only displaying business conversations only. This also has the benefit of not confusing Play Store. This isn't the best way to do this probably, but it works. If you need to check your personal account, just sign in through your browser. This also prevents prying eyes from looking through your gmail app and seeing something personal.