strange things happen while meditating?

[CØSMOS]

I started meditating recently, im not sure if i am doing it right or not, i simply lay flat on my back in bed then relax and watch my thoughts as they come and go. when I do this, strange things happen. i start feeling a sensation that shoots up and down my spinal cord, kinda like a electric sensation, it gets very powerful the more I pay attention to it. As i am watching my thoughts, I noticed that my mind will begin to loop the same thought over and over, the thought it loops varies, sometimes it would be a sound, word or phrase and other times it would be a image. its like my mind repeats the same thing over and over and this induces me into a trace like state of some kind. what ever my brain is looping gets faster and faster with time, eventually its like my brain just breaks and it no longer produces any thought, everything just becomes extremely quiet and still inside my mind.I get the feeling that everything is ok profoundly strong, its very pleasant. this is when i start seeing images as if im seeing it with my own eyes, last night i seen a block of wood with carvings on it, at first the symbols on it were blurry, i actually had to adjust my focus on them as if i were adjusting the focus of my eyes. they became clear but i have never seen anything like them before, they kinda look like the stuff you would see etched into stone from ancient times.
this image would soon fade away and then another image will pop up, after a few minuets i was jolted awake out of this trance like state because i thought i was hearing something next to my bed speaking in some strange language, it was like " DA DA DAAA DA D D DAA Daaa" no lie, was literally only "DA" being used in different tones, obviously i looked over and seen nothing was there, my brain just thought that someone was there saying "Da"....
im oddly ok with my brain breaking and begin tripping out, how ever, ever since last night i have been getting scratched by something...something that i can not see. it starts as a tingling feeling then grows in intensity until it becomes a burning sensation, after this burning pain fades away, i am left with a nice red scratch on the part that was burning. just since last night i have been scratched 4 times like this....and now, i even feel this sensation of a ball or a ball of compressed pressure directly in the middle of my spine, it actually hurts a little bit and its been here all day.....

has anyone experienced anything like this? what exactly is going on when i see the images, am i meditating the proper way? can my brain freak out and think my body is being scratched which causes my body to react as if it were scratched? kinda like a placebo effect?