You're not cooked but you're in a position that requires some honest self-assessment and a focused strategy.
What sections do your section scores line up to?
Great scores on ACT and SAT are not an accident. It's a large degree of skill and focus, so have heart that you can do it.
You've got two scores in the 515+ range and good daily prep work.
That being said, you've got inconsistency in your scores trending towards lower than 520 scores. Without knowledge of specific sections, it's hard to advise on what specifically you need to focus on.
Honest truth: You're not doomed for a high score but you're not trending reliably towards a 520. With this time left, the most productive goal to think towards is not "crack 520" but rather "maximize improvement in the next month". You can catastrophize "OMG only a month left" or you can take it by the horns and say "great, still a month to learn and improve" If you're missing questions due to poor reading or a certain concept not being strong, you could easily pick up points.
A few things to consider are: doing more sections every day - full time passages daily. Stamina improvement and review improvement. Focus on weak sections of the test / sections you can pick up those easy points.
Be confident - you've hit 517 before, that means you shouldn't be dooming about your score - lock in and change your goal.
A last thing - Anki is great but it's not the same as doing timed test work. Fact recall, invaluable - active learning, meh.