first....welcome from Texas!

next, you've got a lot of good advice, especially from Pax
and I'll add, my wife was leery about me carrying a pistol all the time when I got my first one, she'd even been around hunting, etc throughout her life so it wasn't a gun thing, it was just the thought
That was almost 10 years ago when we were married. She's had her CHL for 2 years now She was finally convinced of being prepared to defend yourself and having the right tools, training, and mindset to do it. She carries a Glock 26 of Keltec P11.

As for your 45 vs 9 issue, you are a good sized man, I see no reason why you wouldn't be able to handle the 45, thats what I'd go with (especially since you have 10 rounds limit, look at a Glock30)

good luck!