Lidocaine for the mouth is RX only.
We have a topical spray for the skin at 4% OTC but it cannot
be used in the mouth/mucous membranes because of the inert ingredients.

If your spray was designed for oral use, I doubt it is causing
paresthesias for you.

Some people can be allergic to lidocaine (and other --caine type anesthetics) but that is not common.
http://content.karger.com/produktedb...M2004208002109
There are warnings on benzocaine type oral products for children, since they seem most likely to react.

http://sciencelinks.jp/j-east/articl...02A0571727.php

When people feel "nervous" after an injection that is usually because of the epinephrine that is added to it, to make it last longer (dental).

However, all people are unique. You could just be having an idiosyncratic reaction. The amount of lidocaine from one
small application is very small and a typical allergy would affect other places on the body, not just one location.

You may also be very suggestible...so that if you expected a reaction, your mind created one. Don't underestimate this.
When drug studies are done, often people are weeded out in the beginning, when all subjects get the placebo for a short time. If people react strongly to the placebo they are dropped from the study before the drug is even given! This is controversial but used often for antidepressants trials and other psyche medications.