A sales call is just like the opening of a Broadway play. A critic's review can make or break the attendance, the box office receipts and the revenue. Take nothing for granted. Be on time or 15 minutes early - even if you wait outside. Know where you are going. Getting lost in this day of Google Maps reflects poor planning and may be indicative to your prospective client of how you will be with their transaction. Give careful attention to your appearance and exude the confidence and success that corresponds to your industry, client expectations, and your personality.
Every interaction is important, but not life or death (literally!). Avoid the urge to "spray" your pitch. If you have lost control - especially at the opening - it might even be best to offer another meeting rather than give them the quick pitch resulting in a rejection (not an objection).
Don't worry about what others think about your temporary failure.
The added pressure of expectation only constricts your ability "to be." While there are people that need to get dispositions on your sales effort (to measure the Law of Averages) it does not mean you run down the litany of things that went awry. That usually turns into a "gripe fest" and takes a teachable moment and turns it into a series of "here's what's wrong with them" excuses.