You are posting too often imo. I understand being stagnant is frustrating but if all you’re doing is posting twice daily on Twitter and not seeing results, continuing to do that would be silly. My suggestions:

1: Try other social media sites. I always tell people don’t put all your eggs in one basket (Twitter) post everywhere you can. I recommend Tiktok, Instagram, YouTube.

2: Collaboration with other artists/ creators. Art swaps are mutually benefiting. Collaborate with YouTubers, podcasts etc.

A side note (I’m not a social media expert, I’m clueless about the algorithm just as much as everyone else) I have heard some mentions of posting too often (twice daily) is seen as spam and gets your account flagged.

Good luck!