Hi dere ... now wat u say is pretty much a trait of anxiety. Lying involves taking responsibility of this false picture u have just created so dat no room for doubt is left. The mere thought of failing to convince the person concerned makes u apprehensive and worrisome. I think u have been a person who thinks and and is sensitive too. Right and wrong are variable and depend on wat frame u choose to look through. I don't think it has anything to do about ethics in  ur case. Yes this is amenable to treatment for which u need to consult a counsellor/ psychiatrist. There u can learn to boost ur confidence which helps u in overcoming anxiety and apprehensive thoughts ( besides telling a lie of course ;) Hope this helps u but still feel free to raise further queries in this regard ( using follow-up option) Thank you n take care.