MS Issues Since 7.2

I've posted this already in technical support but I didn't receive any responses. I'm posting here because I'm desperate and curious to see if anyone else has had similar issues. This has only been happening since 7.2.

I periodically get a severe rise in MS while playing, it usually starts off gradually with a few minor lag spikes but progressively gets worse until my lag spikes last for several minutes at a time and I am unable to do anything whatsoever. This will go on for 10-15 minutes then revert to normal. This happens at least once an hour. Usually in dungeons.

This has made progress impossible. I've attempted to complete a dungeon quest three times but I was removed from the group all three times because my MS would suddenly go from 30-2000 and I was unable to play for several minutes at a time. Not to mention difficult content simply not worth attempting with these issues.

I've tried deleting all addons, power cycling my router, renewing IP & flushing DNS, reinstalling my antivirus in case it recognized the update as unknown software, disabling proxy settings and needless to say I've closed all background apps. Nothing has helped.

Can anyone offer any help whatsoever? I'm at a complete loss. I feel I have no other option but to quit. This issue is ONLY for WoW; all other games are fine and while my WoW rises to 2000 MS, I can tab out and open web pages at the usual speed.