Red, Hot Rash On Chest When Nervous. Taking Beta Blockers And Muralax. Help

Hi. When I'm nervous I get a red hot rash on my chest & works it's way up my neck & face & onto my arms. I also get this rash randomly when I'm having lunch at work or in the office doing work. I don't know if this is all due to anxiety or if it is a heat issue or another medical condition. I have tried beta blockers but I don't feel they work & i take muralax when I'm feeling anxious but they stil don't help me all that much & just make me tired, Xanax helps but I can't take these everytime I'm nervous. Also, when I'm at work (assistant manager Aldi) if an area manager or someone higher then me comes in I get very nervous & I straight away get a rash & it's very noticeable. I also get nervous when someone I know comes into work. I need to find an answer coz I have to do presentations, speak at staff meetings, interviews & communicate with area managers & directors but this is really holding me back & starting to rule my life :(