Getting your game on multiple platforms is definitely good. I wouldn't recommend "spamming" but it's a good idea to post about your game in several locations. Itch is just one community, and there will be players out there who would enjoy your game but aren't already looking at Itch. And if you haven't been already posting about your game before it was released, then who will know that it is finished? Nobody... you are just relying on random passer-by to click on your game. And some of them did, which is good! Your game has only been out a week - give it time. Updating with fixes and new content gives you an excuse to post about it, increasing your exposure. Participate in things like screenshot Saturday, or the 1 screenshot per week thread here on the forum.
Another good way to increase activity around your own page is to comment on other people's pages. Play people's games and give ratings, follows, and meaningful feedback. Some of those people will in turn take a look at your projects, and in the meantime you'll be contributing to the community and helping other developers, which makes you more memorable to people than someone who only asks for attention directed at them.
If you just publish games for fun, that's great. But you shouldn't expect many people to play it if you didn't really do any marketing. There's so many games out there, what are the chances that any random person will stumble upon yours? Very slim. You have to tell people about it. And yes, a lot of people will download it and never say a word. Many players will not take the time to leave a comment, even if they liked the game, so you just have to accept that. Focus on building up your own reputation, making connections, and doing a little advertising here and there. Promote yourself in more than one place.... without a huge amount of extra work you can have a Facebook page, an IndieDB page, and so on. A lot of your post content will easily translate from one to the other, so it's not like you have to write 3 separate devlogs for 3 sites. The point is you want the chance for people to see your game whether they are browsing one site or the other.