Thank you so much for the reply. And your advice definitely will be followed.
I don't know why I didn't bother to look for certification. Very dumb of me.
I found his gym at a site called Powerlifting Watch.
He was cheaper than everybody else and seemed like he was eager in wanting to get me in-- he had called me multiple times after my initial talking to him about one day, at a future date, coming to see him at his gym and maybe joining.
There were only 2 other powerlifting gyms that specialized in the olympic lifts and the powerlifting ones like deadlift, but they were much twice his price. So, I stupidly slapped down the money for a full-week of private sessions.
When I told him throughout the first couple of deadlift sets that I wasn't feeling anything at all in my glutes, or legs when doing it and that it was all concentrated on my lower back-- he said that that was just a "weak point" in my body that, with more and much heavier lifting, would solve itself and eventually go away.
When I couldn't get up to walk he did actually help me in stretching out my body so that I could, though.
Concerning sciatic nerve interference... does it ever go away?
And what is puzzling me is what could possibly be causing interference with it if the spine isn't compressing anything? Isn't that or a herniated disk usually the cause of that? It's hard to imagine a simple muscle sprain or strain causing this.