I'm getting sick of the lag

[FrozenMind]

The problem is quite simple: I barely succeed in getting into the game, when I'm in I get lag spikes and then disconnect. This started just recently, this week.

I called the ISP, they say everything is fine + heRO usualy works for me.

Is there any way to get rid of this?!

P.S: Please write all the possible options, it's too long to tell what things I've been trying to make it work.