Was wondering if anybody has similar experiences or any insight into what this might be..

I'm 24 year old male that suffers from a bit of anxiety and depression. I believe this started after I started taking medication (Paxil) for it and has continued even after I've come off the medication. It happens once or twice a week and some experiences vary a bit..

It can happen either shortly after I lie down to go to bed or when waking up in the middle of the night or morning. I feel like I'm 100% wide awake, I'm normally lying on my side and I can see what's in front of me and can hear the TV or the fan if I've got them on.. and I feel the mattress beneath me breathing, or moving up and down very slowly and rhythmically. It mostly feels like I'm being lifted along with the mattress from the waist down. If I try and move to confirm the moving sensation, I can't move my legs, or can only move them very slightly. I think more times than not, I actually fall back asleep after the episode is over only to remember it in the morning. However, there were a few occasions that I felt like I was being smothered and couldn't breathe. Those occasions freak me out so much that I can't fall back asleep and am often up the whole night with the lights on (tonight lol).

At first I thought it was something supernatural, but I've since moved and am actually in a different bed than the one I was in when these experiences started. One being a futon mattress and this one being a memory foam mattress.

Anybody had similar experiences?