Help- I think I had my first seizure

So the other day I was super tired so I slept in really late only to wake up with an upset stomach. I thought I needed to poop since I was nauseous so I headed to the bathroom. When I sat down on the toilet I got very dizzy and that is just about the last thing I remember before I blacked out. I came to on the floor ( I was unaware of what was happening or where I was at the time) I felt as if I was dreaming because my thoughts didn't make sense. Even though I was partially conscious, I couldn't control anything about my body-- couldn't open my eyes or stop myself from convulsing and flopping like a fish. I remember hearing my bracelets dragging and hitting the floor like I was drumming on the floor with my hand. Once it was finally over I got back on the toilet confused, embarrassed and scared and started losing control of my bowels (diarrhea) and started sweating profusely. I then got a headache and got very shakey. It took me about 20-30 minutes to snap out of the daze I was in and be able to think the way I normally do. I really feel as if I may have had a seizure but I feel like I'm not supposed to remember it like I do-- even though at the time I wasn't aware it was a seizure until after I fully became conscious. 

I would love any feedback anyone can give. I am a 21 year old female if that means anything  

Also, I was in a bad Car accident about 4 years ago where I had significant brain injuries (skull fractures, blood clots and bleeds in the brain, multiple concussions, etc) and I also recently got my head cracked open and needed to have it stapled shut-- I haven't felt the same since then.