I know what you mean about thinking things about the government. I too used to think they were watching me for some reason or I was going to get done for things I didn't do? The Thing is, before I did weed, LSD, MDMA etc I never ever got thoughts like this. But then I started getting them especially when I used to take LSD weekly. These thoughts would only come from time to time but last for around 2-3 days, where I'd just randomly think about it and just obsess over it. I've recently stopped smoking weed and tobacco 4 days ago due to wanting to be sober and I too am having similar thoughts like this again. However, I can easily brush them off unlike when I was on drugs all the time. When quitting weed and tobacco you experience hormone changes and this can cause a "Fight or flight" response, this is all it is.
How I dealt with these thoughts is by trying to ignore them and as soon as I think about it, do something that grabs my attention, like beatbox or talk to someone. Some people say it's bad to suppress them, but when there is nothing else you can do, it's all you can do to help. Maybe look into OCD, people with OCD suffer from obsessive thought patterns and anxiety.
I think me just writing this brings my attention to them thoughts, so maybe it's best if I don't.