I didn't even know if I should respond to this because I feel like i'm the bearer of bad news and I don't want to be the cause of anyone's worry. But yes, I would personally be worried. There is a telegram group where the CEAC data is being provided every 2 days or so and based on my review of it, they have currently issued 52,623 visas and potentially another 1000 via adjustment of status (could be more). Over the past week they have been issuing 450ish per day. So I agree with Britsimon that the 55,000 cap will likely be hit on Tuesday. Whether or not they issue more than the cap is anyone's guess.
My advice here is do whatever the hell you can to bring your interview forward. I know some people get lucky and win the lottery on their first or second try but it took me 12 years to win. Some people will never win. It's the opportunity of a lifetime so do whatever you can to bring your interview forward as soon as possible. That's all you can do really. Any correspondence to the consulate/embassy needs to be worded very politely and not pushy. Try to make them sympathetic to your case and let them know you are grateful for their time and hard work.
Best