Sourdough stopped rising?

Hi! I’m VERY new to sourdough (like first time EVER). I started my sourdough on the 1st of January following a tiktok creators method (@okaycoolgigi), and so far I’m LOVING the process. On day 1 nothing happened. Day 2, the sourdough ROSE! It almost came out of the jar! Day 3 the sourdough rose as well, not as high but still to the top of the jar. Now on day 4 (I’ll be feeding the sourdough for day 5 in 6 and a half hours), it didn’t rise at all! I’m so scared that I killed it!! It still had the bubbles and is quite smelly, but not like nail polish which someone said means it’s dead? I’ll feed it today and hope it’s fine, but I want to make sure I didn’t do something insanely wrong 😭