When you first came on here dxm I was wondering if your name referred to the drug found in cough syrup that teenagers often "robo-trip" on.
I had a friend I used to smoke weed with all the time back in high school who got really into taking dxm, it eventually made him noticeably significantly slower. He went from someone with average intelligence to someone with below average intelligence and was obviously a bit out there from then on.
Any "meditative" state that is induced with the help of drugs is not going to be a meditative state that the Buddha would have suggested one should cultivate. It seems to me that you're just getting high on dxm, which allows you to stay motionless for long periods of time and bliss out while being aware of it, this is not jhana.
Also, you are taking dxm way too often. Basically you're saying that you have been overdosing on cough syrup every few days for a month in order to meditate, when you think about it that way, doesn't it seem rather silly?
Seriously though, you should lay off the cough medicine.
"I don't envision a single thing that, when developed & cultivated, leads to such great benefit as the mind. The mind, when developed & cultivated, leads to great benefit."
"I don't envision a single thing that, when undeveloped & uncultivated, brings about such suffering & stress as the mind. The mind, when undeveloped & uncultivated, brings about suffering & stress."