[Relaxing] I am having a panic attack, Reddit, please help me

Today, I was at a party with my girlfriends family. I was going to drive home, so I didn't drink anything but apple juice and some soda. When we were at the party, we decided that I would drive some of the family's friends home, which was quite a long drive. When I was driving, suddenly the cops came and pulled me over. They told me that some people driving behind me earlier thought that I was driving unstable, and had called the cops as they thought I was drunk-driving.

The real issue here was when they pulled me over. When the cops walked over to my car, i suddenly started shaking, and I felt my heart beating extremely fast. As I didn't want my passengers to be worried, i focused a lot, and managed to stop shaking. They gave me an alcohol test, which was negative, told me not to worry (I think they saw how stressed out I was) and then I got in the car and drove away.

I remained calm until i dropped off my passengers, and started driving towards my apartment. On my way home, a car behind me started flashing its lights repeatedly on me (in a tunnel), and at that point, I freaked out. I drove off the highway, and took a longer way home, just to get away from that car. When I parked outside my apartment, i just sat down next to the car, shaking extremely and I started crying, unable to stop.

When I got into my apartment, which was hard (as I didn't get my key into the keyhole), i just sat on the floor, crying. As I am writing this, I am starting to hear things, and I fear I won't be able to sleep tonight...