So support it with weapons and whatever you want. But don't commit economic suicide in the meantime. Then you won't be able to support ukraine over the long run anyway.
What economic suicide ? It's not exactly a balanced struggle. It's painful for Europeans, but it's deadly for Russia. You can't bankroll Ukraine's up-scaling and fuel Russia's economy at the same time anyway, it doesn't make sense.
How do you do that with 40% less gas in 1 year? You can't, because you will have rioting in the street, you will have people literally freezing to death, and no green politician will ever get elected again.
Oh, and btw, what's the answer now to this gas shortage? Burning more coal and firewood. So your proposed vision is doubly going in the wrong direction.
This isn't like switching from windows to linux. It takes years, and people actually die in the meantime if you get it wrong.
It's not 40% less gas. Europe managed to mostly fill their storage tanks over the summer, and Germany has 6 LNG terminals coming online in December. So it's going to be only 15% less gas. So no riots, no freezing to death.
Support and sanctions are two seperate things.