Without seeing your audiogram, it’s hard to have a good idea, but since you said that your stopped using the HAs that you had from 6 years ago, I’m guessing that perhaps your hearing loss is probably moderate and probably mostly in the high ends, with no loss or only mild loss in the lows and mids. That’s probably how you’ve been able to get by without wearing the HAs so far. But again it’s just a guess. Were you fitted with an open dome? If yes, then this probably confirms my guess.
Your issue with tinny sounds and hard to correct background noise is typical with wearers of open domes. The big vents in the open dome will let the amplification of the lows (if any even) escape, resulting in tinnier sound. Don’t know if you have streaming or not, but streaming from a device will also sound tinny because the lows also escape and there’s no natural low to make up for it.
It will also let all the background noise in naturally so it’s usually harder to cut out background noise when you’re fitted with open domes.
I’m not defending your audi, I think you should dump him for not even give you your audiogram upon request. But if you’re fitted with open domes, those issues are harder to fix with open domes, that’s all.