Your debug log shows that Pi-Hole is working properly. Are you seeing the queries from the client and replies back to the client? Check
/var/log/pihole.log, and you can live tail this log with
A few unrelated notes from your debug log:
You are running Jessie, which is nearing EOL. Pi-Hole supports both Stretch and Buster if you decide to upgrade. Note that you can upgrade in place without a clean reinstall.
Your long term database does not appear to be functioning.
[2019-10-29 19:19:46.624 29795] SQLite3 message: cannot open file at line 38452 of [0eca3dd3d3] (14)
[2019-10-29 19:19:46.624 29795] SQLite3 message: os_unix.c:38452: (2) open(/etc/pihole/pihole-FTL.db) - (14)
[2019-10-29 19:19:46.625 29795] check_database(14): Disabling database connection due to error
[2019-10-29 19:19:46.625 29795] Creating new (empty) database