Why was I patted down at the airport?

So this happened at the beginning of march but it still really bothers me. I was at the airport with my dad and for literally no reason they said they needed to pat me down. Then they asked if i was comfortable with my dad being in the room (cause he asked that it would be in a private room [i have anxiety]). And then it happened and it took forever, at least it felt like forever because i was silently having a panic attack (i HATE people touching me). Then we missed our flight because of it. And I'm kinda traumatized.
What? Was? That? For?
(I'm 15 btw)

Anxiety is a normal emotion, and person on a plane may have anxiety for a number of reasons, one is mental illness and among the others is hi jacking a plane. If you have anxiety I want you searched every time. You behavior draws a strike.

You were patted down for security reasons. Whether you behavior or random factors played in, if you agree to go through security you agree to this process. I find it hard to believe that the pat down took so long that you missed your flight if you arrived to the airport in a reasonable time. If you were rushing and acting strange this could have also contributed to the pat down.

Anyway you look it is, you are subject to TSA regulation and procedures to get on an airplane. That is why some people choose not to fly.

If you are traumatized by a pat down, I suggest seeking some counseling. It is not a bad thing or a sign of weakness, mental illness or whatever, it is just that you may need some assistance working through some things.

I have been patted down before for unknown reasons. It was no big deal and didn't take very long. Now you missed you flight, why were you running that late as pat downs do not take long? Sounds like you would have missed your flight anyhow.

(If it took 20 minutes, then you better tell the rest of the story as it does not take this long. You are not telling everything.)

You were patted down for security reasons in an effort to not have planes blown up.

Sometimes it is random. Sometimes it is because the scanner found something. If done without freaking out, it's a 15 second process. It's happened to me. It's happened to my family. It's happened to people in line with me.

Probably because of your huge bulge

TSA requires that x amount of people per hour must have secondary screening. They usually just say, next person through the scanner and there you were.

Its random
If you panic that easily you better give yourself a lot of extra time everytime you fly because it cash happen again
If you missed your flight because of it you/your Dad did not allow enough time
Having much experience flying and having been patted down or having my traveling companion patted down on many occasions when you say it took 20 minutes I know your whole story is BS

Of course there was a reason, but they're not obliged to tell you what it was. It might simply have been that they were checking every 23rd person, or perhaps your physical description matched that of someone they were already looking out for.
It's not a big deal, and I really don't believe you missed your flight solely because of this.

You are not relaxed but showing anxiety symptoms
at the airport hence the extra security measures

It could have been for a number of reasons - it could have been random, it could have been that something showed up on the scanner, it could have been that you were acting suspicious, etc. I've had to be pat down at the airport before. It never took 20 minutes and it was never a big deal.

If that 20 minutes made you miss your flight, then you were WAY late getting to the airport. You should be at your boarding gate at least 30 minutes before departure. There's a chance you may have missed your flight anyway - they close the doors anywhere from 10-15 minutes before departure.