Anybody with experience on passing out or fainting?

I have had a problem with passing out/ fainting. I don't know what is causing me to faint. I normally feel fine but the other night I was coming home from work, sat down was just relaxing watching youtube then all of a sudden I just felt super off I felt like I couldn't think at all. I leaned back in my seat and I started to sweat. My hands felt heavy everything was was like weighing down on me I tried to relax myself as much as possible. All of a sudden all the sound in the room felt like it was sucked out of my ears. And all I saw was darkness. When I woke back up I had thrown up on myself and in front of me. The puke was like super foamy.. Not like normal puke. I had no strength in my body to even get up yet. My friend was there we stay in a camper together and he had said something to me but i couldnt make out what he said. I then felt the worst cramps of my life in my stomach. It was like I was having a contraction. It was very painful and lasted about 30 mins. I asked my friend did i wake him up with me puking and he replied that the shaking was what woke him up. I was surprised I didnt remember shaking. He said it looked like I was having a damn seizure. I just really wanted to know if anyone else has a similar story? If you have ever passed out so hard that it looked like a seizure?