You can quit. It's OK. What you are doing is hard. It is the definition of monotony.

Call after call. Voicemail after voicemail. Email after email. How many times today (this week, this month) have you asked a secretary "Can I speak with…"?

It's not just the activity, either. It's the emotional drain. You have to sound happy on the phone, even though you are worn out. You can't tell that gatekeeper what you really want to tell him/her, and holding back emotion is just as taxing as creating it, right?

Then, there's the mental toll. How can you endure another person that just doesn't get it? You know it will happen 100 times today -- they are just going to say "no" so they can move on. And then there is your boss. He's on you again. Doesn't he know you have tried everything you can think of? That you are working as hard as you can? That you, too, hate your numbers?

Those are real barriers to your success in sales.

What do you need to do to overcome them? PUSH.

Push to make the 51st call of the day. Push to leave the 37th voicemail. Push to look up the 42nd email address. Push to sound happy…to actually be happy and excited. Push to hold back frustration. Push yourself to hear "no" another time. Push to find the answer your boss is trying to help you find.

Barriers like the ones above are tall and wide, but they are all paper-thin. If you give the slightest push to get through, you will be on the other side. Your default setting is to stop. Sometimes, you don't even realize you have made a decision to stop until you are already standing still. Be aware of the decision to stop, and rather than letting the barriers kill your momentum, decide instead to PUSH.