What do I do if my country has been neutered when it comes to left-wing activism? My only option for a party/org to join is a demsoc party which is seemingly pro EU and pro NATO. What do I do? Should i just focus on bettering people's material conditions by working for charities, try to make my own little group, or maybe something else?
There's no way you're the sole left person in your country. In order to stay sane I'd suggest finding where the others are.
People with left politics but no party outlet can usually be found in orgs that work to improve material conditions of the most exploited (homeless, refugees, sex workers). They are also typically involved in climate and anti antiwar protests so you can probably find them there. They also often get involved in municipal politics pushing to get the most left person elected possible. Check radical bookstores, screenings of radical films, etc.
You are not alone, and you can't do anything by yourself.