I still have loudness issues, and am about the same amount of time post op. I do think some of it will just need time, as the recent scope said I had incomplete glottal closure, which I'm sure can contribute to this. However, a few times I have been very loud when not thinking about it at all (e.g. almost in a car accident so I was screaming lol), so I think we're probably speaking a bit wrong still.
The Yeson exercises I posted a while have that 'ing ahh' exercise, and you should try it. I'm able to get very loud when doing that one, but it's hard to translate into general speech.
Hopefully some further along than us can comment.