Greening out every time I smoked weed

I’ve been smoking weed for a while and I used to smoke A LOT I would be able to smoke multiple zoots in a row and still have the best high One day I smoked some weed and after a couple of puffs I completely greened out and was freaking out for hours and hours After that I quit for around a year, recently I have been trying to smoke again but now I green out every-time I’m not usually that paranoid anymore cos it happens every-time so I know I won’t die But it is still a horrible high and just way too intense even if I don’t have a lot Does anyone know why this is happening and what I can do to stop it??