TLDR: New user, 40mg. Intense vibrations and OBE but the only visuals I'm experiencing are patterns when my eyes are closed. Is this normal?
I'm looking for help and guidance from some of the more experienced users out there

Since I've joined this forum, everyone has been very kind and helpful. I really appreciate it.
About me:
-29, healthy and active
-I only have about 1 week of actual first hand experience with DMT. My doses so far have been: 5mg, 15mg, 20mg, 20mg, 30mg, 40mg.
-I'm not on any meds except some aspirin or tylenol here or there
-Method of administration: Sandwich method with mullein leaf (not cannabis). I'm not a smoker but I'm pretty sure I'm taking very large hits from my bong.
-My most recent trip: 40mg sandwich from a bong
-Setting: dark room with 2 sober people. music with jazzy steady beat playing softly in the background.
I took 3 LARGE hits. On my second exhale, I started to see that my hands were blurry but had sharp edges. It reminded me of the "motion blur" feature in Photoshop. After my third exhale I said "I'm gone" and closed my eyes. I instantly felt my body disintegrate and felt like my consciousness was being shot out of a cannon. Then the most intense vibrations and high pitched squelching noise filled my surroundings. It was so strong I felt like my head was going to pop. This entire time there was a beautiful wall of patterns and fractals dancing in front of me (my eyes were closed). But it wasn't bright... It was like watching a Flash animation of blue and green designs on a black background.
While the vibrations are getting stronger, I hear some kind of noise nearby. Because I had no sensation of time, my body, or my breathing I thought it was probably paramedics in the room. Either that or I was in a coma in a hospital. I found out later that it was actually just my friend walking around. The vibrations and ringing noise kept getting louder. Part of me was fighting it and the other part was saying "it's ok, you've heard about this happening to other people, it's just your brain tuning in". But, my head never actually "popped".
Eventually it all subsided and I came back to awareness. I was told that I was breathing fine but my body was stiff as a board because I was so tense. When I came out of it, I wasn't anxious or scared, I was just in awe. I could only say "wow... woa, holy fuck, whaaaa, etc" for about 10 minutes. I was in complete astonishment at the feeling of leaving my body.
Now, the same spice at even lower doses (25-35mg) gave my friend intense CEV and OEV. He was seeing light splashing and being sliced across the wall, snakes, light cubes, and all sorts of other objects. He said he never broke through at those low doses. I believe him because his 50mg doses were described completely different.
My question is this: Is it normal for a sub breakthrough experience to have such little visuals? Does this happen to anyone else? If so, what could it be?