What happened? SP?

Last night I was laying in my bed and it had been almost three hours that I had not moved one bit at all. I had my eyes open and was just thinking I had no intentions of having anything happen.

But then very rapidly the room around me started to shift and shape and things moved all of the place. It looked and felt like the room was spinning but I still had my eyes open. This was so frightening, my heart was going a mile a minute, and I had no idea what was going on. Then while my eyes were still open I went into SP and though my eyes were open they just completely blacked out.

After that I decided to close them and try and see where the SP would lead me and 5 times I would enter a dream for about 25 seconds and the instant I noticed it was a dream it would just end and I never actually got to become lucid.

So I guess I am wondering if anyone else has had the open-eyed visual distortions like I had last night, and also if anyone has some hints I can use to go from an SP to being in a full blown LD.

Oh and no, I was not under the influence of any drug I was totally sober during the visual distortions.