It would hurt a lot economically to stop buying gas from Russia right now. Even during the Cold War Europe bought gas from Russia. However Europe is probably going to try become less dependent on Russian energy in the long term, that's been stated by a lot of politicians lately.
Yes it would hurt but 1) the damage would be larger in Russia then Europe 2) Europe has a much bigger economy to take up the slack.
Fuel exports to Europe are 15% of all Russian economic activity. But Russian energy is only 25% of just the fuel sector in Europe. The natural gas that is the lifeblood of the Russian economy accounts for just 5% of European electrical production.
If Europe was willing to absorb some costs they could squash Russia like a bug. Russia's economy is almost tailor designed to be vulnerable to sanctions. European politicians aren't eager to take that step but it's a very credible possibility in the new future. When people are talking about the possibility of major armed conflict seriously a 5% substitution of electricity with higher cost alternatives doesn't sound too bad, does it? In fact from an economic standpoint Europe would be doing itself a favor by stimulating it's depressed economy with new energy investments.
You scaring shits out of me

My family lost all bank savings in 90s and parents wages was delayed up to 14-16 months at peak. Guess what, we still here. You really understimate endurance and little needs of slavs, thats biggest mistake West usually tends to make.
Besides, some EU countries completely depend on our gas (liek Poland is 92% or something) and belt of mediterranean countries quite dependant on our tourists money (it's millions of ppl a year). There is much more to that list but I cba to provide links, because any prooflinks is going to be ignored or refuted anyways.