Using oxygen

I visited my pulmonary doctor yesterday and he emphysized the fact that I needed to use oxygen -I had lung volume reduction surgery in 2001 so you would think I'd have no problem with oxygen - wrong -  I have no problem with using it at home but I'm really uncomfortable (vain I guess) using it outdoors - can anyone out there using oxygen help me feel more comfortable about it. any advise is dreatly appreciated thanksRoe