Based on the TX penal code, you can display/produce a weapon to threaten "death or serious bodily injury" if your purpose is limited to making the other person think you will use deadly force if necessary.
Sec. 9.04. THREATS AS JUSTIFIABLE FORCE. The threat of force is justified when the use of force is justified by this chapter. For purposes of this section, a threat to cause death or serious bodily injury by the production of a weapon or otherwise, as long as the actor's purpose is limited to creating an apprehension that he will use deadly force if necessary, does not constitute the use of deadly force.
You can do so legally when FORCE is justified. That's a more relaxed standard of justification than DEADLY FORCE.
So, the question is, did your situation justify the use of force. Below is the applicable section of the penal code. I've left out some parts that don't have anything to do with your situation.
Sec. 9.31. SELF-DEFENSE.
(a) Except as provided in Subsection (b), a person is justified in using force against another when and to the degree the actor reasonably believes the force is immediately necessary to protect the actor against the other's use or attempted use of unlawful force. The actor's belief that the force was immediately necessary as described by this subsection is presumed to be reasonable if the actor:
(1) knew or had reason to believe that the person against whom the force was used:
(A) unlawfully and with force entered, or was attempting to enter unlawfully and with force, the actor's occupied habitation, vehicle, or place of business or employment;
(B) unlawfully and with force removed, or was attempting to remove unlawfully and with force, the actor from the actor's habitation, vehicle, or place of business or employment; or
(C) was committing or attempting to commit aggravated kidnapping, murder, sexual assault, aggravated sexual assault, robbery, or aggravated robbery;
(2) did not provoke the person against whom the force was used; and
(3) was not otherwise engaged in criminal activity, other than a Class C misdemeanor that is a violation of a law or ordinance regulating traffic at the time the force was used.
(b) The use of force against another is not justified:
(1) in response to verbal provocation alone;
(2) to resist an arrest or search that the actor knows is being made by a peace officer, or by a person acting in a peace officer's presence and at his direction, even though the arrest or search is unlawful, unless the resistance is justified under Subsection (c);
(3) if the actor consented to the exact force used or attempted by the other;
(4) if the actor provoked the other's use or attempted use of unlawful force, unless:
(A) the actor abandons the encounter, or clearly communicates to the other his intent to do so reasonably believing he cannot safely abandon the encounter; and
(B) the other nevertheless continues or attempts to use unlawful force against the actor; or
(5) if the actor sought an explanation from or discussion with the other person concerning the actor's differences with the other person while the actor was:
(A) carrying a weapon in violation of Section 46.02; or
(B) possessing or transporting a weapon in violation of Section 46.05.
(e) A person who has a right to be present at the location where the force is used, who has not provoked the person against whom the force is used, and who is not engaged in criminal activity at the time the force is used is not required to retreat before using force as described by this section.
(f) For purposes of Subsection (a), in determining whether an actor described by Subsection (e) reasonably believed that the use of force was necessary, a finder of fact may not consider whether the actor failed to retreat.
I guess you could try to make a case that you reasonably believed that force was immediately necessary to protect you against the use or attempted use of unlawful force by the other driver, but there's nothing in the law that clearly spells out that you would be justified in displaying a weapon.
It would all hinge on whether a reasonable person in your situation would feel that a person tailgating & shadowing would consititute the use or attempted use of unlawful force. Probably a stretch...
and yes I did feel threatened, How many of you ride and Know what it like to have a car on your ass doin 55 5/6 feet way from your back tire
