Have you been studying?
Rating

I used to teach chess at chess clubs, and I found that when my students learned some new concepts... especially strategic rather than tactical concepts... their results and their rating would often go down instead of up, as they struggled to assimilate the new knowledge into their playing style and make it part of their usual technique.
Only after they had succeeded in "digesting" the new ideas would their results and their rating shoot up to a new high.
I was stuck at 1300 rapid and now just improved to 1600 in 10 days. Did chess.com change the rating system or what could be the reason for this?