When I lay down for a wild session, after about 10 minutes, I get the chocking sensation. I won't be able to breath. I guess i is the starting of SP.

Now, while the sensation starts and goes on for 10 seconds(I'd be holding my breath), I'd start to suffocate. Now, I have two choices. Either I resume breathing or continue holding Breath.

When I resume breathing, this chocking sensation recedes. I can continue holding breath, but my lungs presses harder with every seconds and for how long?

Thank you