Have thin blood vessels. Pressure in head, spine and neck. What could be the reason of this?

Hello Today is the third or fourth time I almost passed out. I was required to stand for 5 hours. 2 hours in I begun to feel hot and cold at the same time. My mother said I looked very pale ( white like a ghost; her words). She felt my cheeks and said they were really cold as well which was quite weird because it wasn t cold in the building. It was just the perfect temperature and I wasn t feeling hot or cold before all this started. I was then getting weaker and weaker. I couldn t feel my head where it was anymore but i did feel some kind of pressure inside my head. It was under my brain and between it and the skull pressing down on my spine and neck . ( it was not painfull) Meanwhile my muscles, joins and bones turned to jelly and my arms felt so heavy as if I had 100kg weighting down on each one. Also I felt blocked from whatever happened around me. I could only see but I couldn t register what I see. No danger, nothing normal, no reaction whatsoever to the outside world. I felt trapped in my own body. I sat down and tried to relax my whole body. Every single bit of my body felt so weak that it could hardly keep itself in one piece and that it was ready to fall appart any second. No matter how much I I would try to calm myself, relax and get over this episode I felt like I had to concentrate to remain in one piece. After I sat down I hoped I would start to get better but it all felt like a roller coaster. Worse a d worse. I only started to get better 5-10 minutes after but then my whole body was shaking so much and then I registered how all this time I felt like I was sweating in waves and now it all begun to dry up. I m 17 and a half, female. Healthy diet. Chocolate any time ( I can never say no to it). 5 7 And 60 kg ( recently taken). No smoking or drinking. Besides having cold hands and feet most of the year no matter what the weather is like I have no other health problem. Cold hands and feet most of the year - thin blood vessels (not enough blood can pass through them to keep them warm like they should be) I always move from one leg to another, move my foot around making the ankle click ( every joint in my body makes a sound). However I do not stand up every day for such a long time in one spot. Only once or twice a week and even so I hate it. I can feel my spine shrinking and my rotula getting trapped between my bones. I m really worried. What could it be?