Help

Hi I’ve been struggling with strong symptoms of depersonalization/dissociation, 24/7 for almost three years now. I’ve never noticed any breaks from it but I’ve tried talking to my therapist about it and she has like no idea what im talking about and keeps dismissing it, even though i need more help. should j get a new therapist ?? Also if anyone has any more info about the symptoms, even though ive been experiencing it for a while now, im not sure if it could have been caused by my heavy use of marijuana in the past ?? Or could it be from PTSD ? I dont know i just get really frustrated about it because it feels like it is literally keeping me from having a job. I can’t remember anything in my life and it feels like my mind is just blank. I’ve tried to just ignore it but I’m so scared this will end up being the rest of my life, and i’m losing my mid 20’s to this, it is so sadenning.