It very well could be a slump or some form of chess tilt which is burning you out. If you really think it’s tilt, then check out my playlist for preventing tilt (especially my second video) https://www.youtube.com/playlist?list=PLTXwNMbhsy4uh2e7swLXpYA-7_2AXTeF3 but since you mentioned puzzles, I’ll comment that puzzles only gets you so far. There’s many other important aspects of chess. This video shares something that held me back for years and I discuss puzzles a bit:
https://youtu.be/kHC2sCF6900?si=9xoBPNjMnJj-EXHg
Anyone else have the same experience? If so, how did you get over your slump?