This is perhaps best understood as a commentary on the use of socially accepted mind-altering drugs, the most famous of which are probably Prozac and Ritalin. Note how the lyrics say it "makes me happy" and "now I'm awesome" which strongly suggest it affects the user's mood.
The literal meaning of "truthagen" would be something that generates truth, which while nonsensical is generally positive-sounding. This term is probably a further commentary on the nonsensical names of designer drugs such as the aforementioned Prozac and Ritalin.
Lyrics from the song;
“Truthagen truthagen truthagen makes me happy!
My mom got me Truthagen.
Truthagen…?
Now I’m awesome!
Wow!
We have it for lunch and tea every day!
Truthagen…”
Truthogen is a drug, said in the album "Truth of the world" in the lyrics of the songs "Max is stable", "Hey boys and girls", "infotainmentology" and "Chemical Miracle".
It's a fictional drug that has been created by the band Evermore. It's said to cure dizziness and tiredness.
churchhurt is where you experience a degree of distance, pain, or judgement from your church community. Essentially, you are just unable to “find your place”. This is prevalent in the Christian community, but can be extended to other religions.
Now that I am an adult I am beginning to heal from the churchhurt that was inflicted on me as a child.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.