Did you use the wizard to configure the traffic shaper?
If yes, you can check on the "Floating" tab whether the wizard has created any rule for the queues it has created.
If there is no rule, then, to be honest, I have no idea why accessing the pfSense box is sluggish when traffic shaping is enabled without any rule making use of it.
Only LAN traffic should be included in the qLink queue, ie, any traffic going to Internet should go into the qInternet queue.
NB: Your default queue is under qInternet, so any traffic not matched by any specific rule, will go into the qDefault rule under qInternet and therefore be limited to a maximum of 2.9 Mbps.