Anxiety issues? I get super nervous and afraid of being judged

Can somebody give me an advice to overcome this? When a client or manager at work calls me and ask for explanation in a very rought tone, I ended up speechless and when I try to talk my voice goes out in a very strange tone, almost like I had no breath to talk, no air in my lungs. How can I get over this? Is it anxiety? Someone has experienced similar? ​