bro tell us what model your dlink model is? if can find QoS inside, please upload screenshot too, thanks.

here is tutorial: https://www.youtube.com/watch?v=K_tNognjjwM

but it seems unifi one doesnt have..so if u need control the wifi bandwidth i suggest add a cheap wireless N at least 150mbps router with IP QoS ability and use the d-link as bridged modem.

so are you able to set bandwidth limit now? for torrents is kinda impossible to use QoS, but for your games can set the ports for your PC IP to high priority.

i mean for some torrent progam like utorrent, it use random port mapping so cant properly limit the speed according to port, so the router QoS cant manage torrent bandwidth unless use hard cap on the user's IP when they torrenting.