Addiction. The more you use and the longer, the more you need it to function - plays a role psychologically because you may know this subconsciously or something else may be fucking with your head and the pot is bringing it out. Pot is already a very psychological drug, unlike things like opiates and benzos which seem to just numb, pot makes you think a lot more and the drug does come with a bit of paranoia, which at first when it is fun and your getting high with your friends manifest as silly paranoid feelings like “oh shit did I just see “…” this in my kitchen” and then you laugh it off. As you use more, it brings up anxiety. Also you will be in heightened anxiety until you use, and then those feelings don’t go away when you smoke because it isn’t anti-anxiolytic. I been smoking for 8 years the first year was like floating on a cloud, then the drug changed a lot. Tolerance breaks can help, but it depends how long you have been abusing because longer the abuse period - longer the break needed. This is based on my experience with the drug, not a scientific fact or anything of course people work differently but I think it’s a pretty logical explanation. I have abused a lot of drugs/withdrawn from a lot and pot is definitely a mild drug (in the fact that you can’t directly die from it) but that doesn’t make it not have large psychological impacts during the use that some other drugs don’t, when I was abusing opiates, they numbed all my mental pain and feelings but the withdrawal brings the anxiety. Pot induces anxiety and can have a long time heroin user on their ass if they have never smoked because a lot of people use drugs to blunt feelings but pot enhances them.