Failed to connect to instance

Been playing quite religiously for the past week, felt no hiccups whatsoever.

Until this morning.

I logged in successfully, and got into character selection screen, nothing's weird here, so I tried to do the same thing I did every day, I clicked 'Play'.

Loading to Oriath was longer than usual, like 20-30 secs longer, and then, bam, "Failed to connect to instance".

I tried 10 more times without luck, already tried restarting my PC, resetting my router, changing gateways on VPN (even turned off the VPN to see if that would change anything, no dice).

Up until now, still no success.

Anyone can help with this?

Update: I tried to log in using a different gateway (Australia) and apparently it worked. I mainly played using Singapore gateway.

Update2: Changing my gateway back to Singapore still results in 'Failed to connect to instance error'

Update3: Turning off my VPN completely (again), tried to log into Singapore gateway turned out to be successful, but with pretty awful lagspikes, I used Mudfish VPN with pretty good stability over the course of the previous week, still don't know what's wrong.