I urge all of you who are suffering from DP to get you thyroid checked. I know you may think that "I got them checked" , just see the TSH level, it should not be above 2 for a normal 30 year old or less person. people who are above age of 40 get TSH level 2 or above. If you have your TSH above 4 , immediately seek medical advice. I had my TSH 4.5 initially but my doctors said its normal [ I am 17 years old. really??? ] After few months my TSH was 8.6, thats when I officially got diagnosed with Hypothyroidism .
This article will make clear the cause of your DP ----> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3961955/