welcome to the forum dude, i too am 19 and iv had hppd for just over a month after i took some mdma, then a little MXE and just, didnt seem to come down properly
i too at first thought i was going insane and it still concerns me now and again but a few tips i have in dealing with it is that remember like normal u will have good and bad days. i thought i was about to be fully healed then it relapsed over the past 3 or 4 days but wel see.
the main thing is stay away from drugs, cafeine, alcohol. try eating healthy, lots of fresh OJ and vitamins etc. and try ur best to ignore. telling urself u dont have hppd is pointless its like ignoring a broken leg..its not gunna help i dont think but dont dwell on it. when u feel good make the most of it, try and live ur life and do things, dont let it hold u back and it should hopefully heal up.