I'll try but it's really hard to keep things brief.
The experiences were really bizarre. During the mushroom trip I contacted some kind of spirit, who I called the 'mushroom spirit'. Presenting itself as a guide and teacher he started speaking through me. Through writing and the dialogue in my head we had a long conversation. Some messages were communicated directly, without the use of language, but I insisted in also writing as much down as possible. It felt like things had to get 'translated' into language for me to understand, which the spirit found annoying and tried to get me to stop writing. Eventually he let me have my way but I felt disapproval.
Several times it appeared as if my body was taken control of. My hand seemed to be moving and writing things on its own. I was amazed. At one point I got distracted and I felt a gentle but firm force turn my head back toward the paper. At one point my face was nearly pushed into my notebook onto a message that I had written in bold capital letters. Quite a dramatic way to make a point.
He seemed mostly kind throughout the experience but there were several occasions where he showed his other side. I protested too much which led to him becoming rather authoritarian. He avoided some of my questions and made me fill in the blanks. He told me we were one and the same, so I guessed there was no point in questioning him. At one point he stated "WE ARE ONE..." When I think back on that message it sends shivers down my spine. Like I was looking into the large eyes of some creature while being put under a spell. He claimed I had merged with him and this was favorable to me. He made a joke about me becoming a mushroom which made us both laugh. He had a great sense of humor.
I've later rationalized the experience as it being a projection or manifestation of parts of my ego. My ego split which allowed me to talk directly to certain parts of myself. But his presence felt very external and 'other'. Regardless, he knew everything about me. Could read into my every thought. Lying or pretending wasn't an option.
During the experience he kept trying to steer me toward traumatic experiences in my life. I assumed he wanted me to deal with issues I had been running from for a long time. But I wanted to keep things positive and I was too scared to look. I tried to communicate I wasn't ready, but he wouldn't have it. During the power struggles he tried to get the upper hand with some weird tactics that gave me a scare. I had started talking to a friend on Skype who was giving me advice but then the spirit started demanding attention again. There were several other occasions where he expressed feelings of rejection and a jealous side when I was thinking or writing about other people or things. Suddenly my internet connection and the music that was playing was shut down. I found myself in my room in the middle of the night in pure silence. The message seemed to be "You can't run". I panicked and eventually managed to restore the internet. I had turned it off by changing some settings, but I had no memory of it. Again it felt like my body has been taken control of. When I realized what had happened I felt amusement from the spirit, almost like he burst into giggling. Mischievous.
The dose I had taken wasn't too strong, so there was a limit to his power over me. Somehow I promised him we would look at the traumas next time and he eventually let me off, again feeling disapproval or maybe disappointment...
After the trip I was glowing. I felt great for weeks and I felt no need to go back and have another mushroom experience anytime soon. I broke my 'promise' and decided looking at old traumas was no longer necessary. But then after visiting a friend and smoking a bit of weed things went bad. When I went home severely traumatic memories started flooding in. Things I had tried to suppress for a long time. I was devastated and it sent me into a deep depression for the following time. It almost seemed like some kind of delayed reaction from the mushroom trip. The spirit had wanted me to look and I had refused to listen, but then it happened anyway.
A month later or so I used LSD. The experience was different entirely but I yet again felt like I was communicating to spirits outside of my own mind. But that's another story.
This is all just my personal interpretation at the moment, and possibly one of many.