Gamedev City [0] is a new community and could be a good place for feedback and finding resources in general. As for sharing demos and collecting feedback I personally think itch.io [1] is pretty good.
As far as game improvement is concerned it's important to get in a growth mindset and keep focusing on improving the game, which it sounds like you're already doing.
Finally if you haven't already I would recommend creating a discord or some kind of forum for you game (itch.io has free hosting for them) just so you can collect feedback from people who are interested and invested in it.
[1] https://itch.io/