Weed,anxiety,stress,derealization

Recently after trying some marijuana, i had a panic attack(I believe) I was at school and was unfamiliar with the effects, I did not like them one bit and was tripping out.. If I concentrated on something(opening my locker) I would slowly see black and almost pass out. I made it through the day and felt normL that night. From then on I have been getting big headaches, feeling faint/foggy minded all the time, lack of sleep, thinking about the day before and wondering if it actually happened and It always feels like some sort of pressure is pushing in on my head. I am too embarrassed to see a doctor or tell my parents, they are the joking type and wouldnt react seriously. I am 15 years old is there any way to help this? I do not want to feel this way forever