Piper At The Gates Of Dawn does that to me too. Worry not, it just means you truly experienced a lot of what Syd (R.I.P.) was trying to communicate.
that sounds awesome! especially the midevil scenery part. i once had a trip where it felt like i went inside my head and all i saw for a bit were weird colors and shapes and.. i cant even describe it, sounds close to what you described though when you said you were about to freak out