Should I be concerned???

So today I slept until 12pm, I was really tired for some reason. It was 3 when I decided to take a shower and I still haven't eaten, I was waiting for my sister so we could go out. So in the shower I noticed I was bleeding really heavily with clots, (I'm on my FOURTH day on my period) more than usual (I'm heavy my first two days, then a medium/low flow from there.) I didn't think anything of it, so I got out and that's when I noticed my heart was beating really fast. I figured that my body needed something for energy so I drank some Gatorade and went to my room to get dressed. That's when it went bad, I started shaking and breathing rapidly, and knowing myself (I had this feeling once before and it ended in a seizure and three days in the hospital) I tried to calm down and control my breathing. I ran to my kitchen and grabbed a banana and took two bites before I started getting dizzy and very lightheaded. I ran to my couch and laid down and I felt like I was on drugs or something. Luckily, my grandma just got back from the hospital and opened the door to me in only a towel mumbling that I'm going to throw up and I need help. I closed my eyes and breathed because I really didn't want to have a seizure or faint, but the horrible feeling of being weak and lightheaded was still there. After a couple of seconds it started going away and i just laid there because I was scared of getting up tbh. What should I do? Was it because I haven't eaten or because of all that blood? I'm 16, 5'5, and 110 lbs if that helps. Is there something wrong with me?