Pushing past SP

Last night was my first attempt to WILD. I felt like I had reached SP but my breathing got really shallow. I'm thinking this is normal as when you sleep you don't need as much oxygen, however, as soon as I realised it I could feel my pulse beating really hard (especially in my stomach) and I need to breathe deeply again which I can feel pulls me out of the SP stage.

Has anyone else had this? I'm wary about ignoring it as although I'm sure it's just natural but I don't want to accidently kill myself through self-asphyxiation :P

The furthest I got was where I started to see flashing images in my mind's eye, I felt really heavy and I could hear footsteps but I couldn't bring myself to try and move as I knew I was close but not quite there. Next thing I knew it was 09:45 and I had to get up and go to college. I'd set my alarm for 05:00 to try a WBTB but I slept through it.

I'm pretty happy I got to SP on my first attempt, but it's hard to push past. Any tips?

SP is tricky, it can have many different effects, the main thing to remember is that its completely natural and it happens either way. My first time it was really hard to make it through, but I toughed it out and it payed off. Theres other induction methods like FILDs, DEILDs, and tactile WILDs that you don't really realize your going through SP, those are good if SP is consistently getting the better of you.

Man, I get this problem too.
After a while of counting breaths or visualization or whatnot, my pulse starts feeling harder, or maybe i'm just feeling it more. I also notice I tend to breathe a bit less around then.

The thing is, I cannot stand to feel my own pulse. It's a pathological thing for me. After about thirty seconds or so of that, I can't take it anymore and shift into another position and try to sleep normally.