Is this sleep paralysis or something different?

I've been working on using WILD technique for a while off and on, and usually I just fall asleep and fail. But I've noticed someone kind of new crop up, and I'm not sure if it's true sleep paralysis or something else. It happens in the morning after I've woken up, on day when I don't have work and can sleep in a little. I get comfortable again and lie(generally on my back) and try to drift off.

That's when this sort of static-y whishing sound starts in my head(or in at least one case, the static accompanied by a flat tone like a tuning fork that won't wind down or stop), and it sounds like it's coming from all directions sometimes. At the same time, my hands and feet and head go numb. This doesn't even take 60 seconds sometimes. If I don't do anything, it progresses to more of me until I panic and the sound is loud and I only move my torso side to side like a person trapped in a sleeping bag without arm or leg movement. Sometimes I can move my feet and hands again after a minute but the general feeling of numbness remains and everything's useless for another minute. My mouth doesn't work at all and I can't speak at all.

I don't see anything when I open my eyes that's out of the ordinary, and my breathing doesn't bother me or go out of my own control. I can speed it up or slow it down, it doesn't really change anything.

These things can also happen if I'm trying to nap during the day in any position. Also, I've felt like I was moving or sinking into the bed or quicksand or being rolled over even though I wasn't moving.

Some of this screams "sleep paralysis", but should it happen so quickly, and only after waking up and settling back down? What's going on? The partial movement thing makes me think twice about sleep paralysis too. If it is sleep paralysis, where should I go from there?

In sleep paralysis you can't move your hands or feet, however if you're able to relax through sleep paralysis, you can lucidly move your hands and feet which can feel extremely life-like. it's more likely to experience SP during a nap because your body is still catching up on last night's rest and you're in a deeper level of sleep. I used to get SP during 30 minute naps.

It's hypnagogia. I cringe when people call it sleep paralysis, but yes, it's the state that can lead to transition into WILD. To enter a WILD, it doesn't matter how long you remain still, just how close you are to REM. That's why it can happen so quickly when you're at the stage of the sleep cycle that is mostly REM (late in the morning, afternoon nap). The thing to do next is remain calm and let the experience happen without too much effort or resistance. It may take a few times, but the sensations will become more familiar and you won't feel panic. There's no danger at all. It may be difficult to know exactly when you are asleep. It you have no vision or you feel a sense of falling, you're probably already asleep but you don't realize it until you notice a more obvious sign, like actually appearing in a new scene. It's a fragile state though, so you want to remain calm, be patient, and wait until you're fully in the dream. Falling through or levitating off the bed are good ways to transition, so don't resist it. Let it happen. You can also visualize a new scene to distract you from the sensations. You might actually incubate the new scene and appear in it after the transition.

Thanks for the name, I knew sleep paralysis didn't quite fit. I always tell myself I'll see it through and actually get a lucid dream out of it then chicken out. My main fear is something like a visual or tactile hallucination of something terrifying. I know intellectually that it's safe but fear doesn't always work that way.

Yes, I totally understand the gap between intellectually understanding something vs coping with real experience, emotion, and fear. I'd only suggest a diverse practice. Sometimes, those weird experiences, even if harmless, can disturb your sleep and affect your waking life or your motivation. So it might make sense to focus on DILD practices during the week and save WILD attempts for the weekends when there's less concern that a bad night or losing sleep will have negative consequences. I think having a few DILDs and/or DEILDs under your belt makes WILD a bit easier because you've explored the territory. It all depends on what fits your schedule but trying a broad strategy can give you more experience and learning opportunities with less downside.