> they don't want cheap gas
You don't strengthen an enemy (Russia) by buying their products. Defence is more important.
> as well as shutting down reactors
A German problem, not a wider European one.
The solution is to accelerate the transition into electric vehicles (including HGVs etc.), renewable energy, and nuclear. Oil is obviously still needed for materials production, air fuel, and so on, but extricating ourselves from situations where oil is becoming optional as fast as possible is the best course, not continuing to buy cheap gas from an aggressive neighbour that's fucking your elections and invading its neighbour.
> You don't strengthen an enemy (Russia)
How is Russia your enemy? They were happy selling gas to you. They were not so happy about the prospect of NATO setting up shop in Crimea nor American missile bases 250 miles from Moscow (remember "not one inch"?), which is where that was all heading. The reality is EU let Americans push them around (both Europe and their Ukrainian proxy) for their geopolitical objective of global "end of history" hegemony/primacy. And that's not even Russian propaganda, the American stink tanks and politicians have talked about this non-stop and out in the open since the 1990s. The Iran war is the result of the same "containment" policy, btw - but they don't have nukes so they received direct kinetic action. I bet if you said Yankee go home and stopped throwing drones at Wildberries (yes, that is all NATO ISR and targeting plus EU financing), made an agreement with the Russians where they weren't stressed about their western flank, then they would be more than happy to get back to selling gas and buying Mercedes. Don't believe me? That's what they were doing before we freaked them out with a coup next door then started helping Kiev shell ethnic Russians in the Russian part of Ukraine in 2014. But hey, pat yourselves on the back and enjoy deindustrialization and decreasing living standards...