Ok last one I am going to comment on for now is the m'am comment, as that is funny and trust me... common. I've worked at several jobs that require CONSTANT customer interation, and after a while people just all start to blur together into some sort of undefinable, soul sucking, blobby monster. The entity. The entity that starts becoming in my mind, 'Ew, why do you want to come here any ways, leave me alone, get out you hell spawn, let me enjoy my misery in peace', but verbally ends up being, "What do you want/how can I help you(off a cliff?) sir or mam?" And that is literal, I actually say 'sir or mam', not 'sir' or 'mam', but 'sir or mam' in conjunction to everyone from body builders to girl scouts. Generally very bluntly, listlessly, rudely, and oftentimes sarcastically in always the most disinterested(although naural for me), voice. It is always some variation of both the sentance and the sentiment. But yeah, don't worry about the customers and how they view you, (at least not to the point where it causes you to actually tear yourself up as you seem to be doing), not saying you have to be absolutely awful (yeah probably don't be), but add a dahs of selfish humor if you need to-you can be just as happy as you seem to try to be making everyone else. You probably get much better results from being courteous than I do with my... whatever that attitude is, so don't get too down about a few bumps on the road.