I have what I think is the same problem since early this week. Only with Uploaded, as both rapidgator and nitroflare remain fast. The DL speed drop is 10 fold slower (from 6 MB/s to now <1).
Here are my logs too. Currently over 500 files in my que.. Will take forever now. When they work, they are fine, just much much slower
25.02.17 07.32.02 <--> 26.02.17 12.17.53 jdlog://5259379150841/

(windows 7, Idid not recently change windows version like the OP did)