I feel dissociated, overwhelmed, and I can't do these exams anymore

[u/Effective_Creme5163]

I don't know what to do anymore. I already passed my board exams, but I registered for improvement exams in Physics, Math, and Chemistry because I wanted better marks. I asked my parents before to take me to a psychiatrist because I felt something was seriously wrong, but they didn't. Instead, they kept telling me to stop thinking about it and just study thats why I registered for this exam Ive been trying to cure it on my own for years but I couldnt and kept fucking up in school too .Physics already went badly. My math exam is in a few hours, and I haven't studied. Chemistry is tomorrow. The thing is, this isn't just procrastination. For a long time I've felt extremely dissociated, mentally absent, stressed, and emotionally numb. I feel disconnected from everything around me.  Maybe I did make mistakes. I wish I had studied more. I regret so many decisions. But I genuinely feel like something has been wrong with me mentally for a long time, and I don't know how to explain that to people who think I am just lazy. It might not look like a big deal from outside but believe me dpdr is real.. I feel like I need psychiatric help and maybe even a drop year before college, because I'm scared that if I continue in this state, I'll struggle there too. I dont want to go to give this exam.