Ah...yeah, whoops ๐ . IT & Military definitely love their acronyms!
But you've got it pretty much spot on! Just keep an eye out for the various companies that are winning defense contracts; I usually keep an eye out on this site to see what's going on out there: https://news.clearancejobs.com/category/defense-contracts/
Once you find one you're interested in, the job listing will usually tell you it requires a certain level of clearance. Depending on the job, some will expect you to already have said clearance, but most will not. The company will apply for your clearance on your behalf, referencing the contract that you've been hired for. Then you get to go through the extremely fun process of a 30+ page background check, where you get to go through the last ten years of your life. Where you lived, who knew you at those addresses, where you've been out of the country, jobs you've held, etc. The very first one I did was in my early 20's, so going back 10 years I was filling in my parents address when I was still in high school! It's really not that bad, but they definitely ask a lot of off-the-wall stuff.
You'll usually get an "interim" clearance a few months after you apply, which will allow you to do your work, but you'll get your final clearance after about a year or so (assuming everything checks out.) Once you've got it, you keep it for 5 years, and it'll automatically be renewed as long as your job requires it, and it can be transferred between companies if they require you to have a clearance.
I actually have this too! For me, it usually happens when my extremities get too cold, and it can take me a bit to even notice it's happening. It usually happens predominantly in my big toes for some reason. For me it just feels like like it's gone completely numb, and I lose all feeling in the digit. I usually break out the heating pad and try to warm it back up until I can feel it again.