Your account's not banned, but HN's software is killing your posts because it thinks you're running afoul of the rule against using the site primarily for promotion—see https://news.ycombinator.com/newsguidelines.html: "Please don't use HN primarily for promotion. It's ok to submit your own stuff occasionally, but the primary use of the site should be for curiosity." Our software detects that sort of submission history and starts filtering the posts once the percentage of own-posts is too high.
On HN, the idea is for people to submit stories that they ran across and personally found intellectually interesting, not because they have something to promote. It's fine to post your own work, as long as it's interspersed with interesting posts from unrelated sources. But when an account only submits promotionally, it feels like they're not participating as a community member, and HN users notice this and flag the posts.
I don't want to discourage you from submitting your own work! But it's best to build up a track record of interesting submissions from unrelated sources, and to intersperse your own articles with those. The software considers submission histories adaptively, so if you do that, your own-posts will eventually stop getting filtered.
If you dig up interesting things from a variety of places, things people haven't run into before, then you'll be perceived as a community contributor rather than someone trying to market something. Particularly good are stories on out-of-the-way topics that rarely or never get attention. The best submissions are the ones that can't be predicted from any existing sequence (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...).
Edits to remove unhelpful comment:
It's probably the system seeing it as duplicate. Or users flagging it because they see it as duplicate or spamming.
If you're asking why that means you're a spammer with a sense of entitlement.
Don't ask what we can do for your blog, ask what your blog can do for us.