Plenty of recruiting stations in Russia for people to go join the fighting in the Donbass. Hell, there's even one in London. And the counter-Russian militias aint exactly picky either (not when they're using people who idolise Oskar Dirlewanger).
Even easier to go to Syria. The Turkish border is so pourous it may as well be a sponge. From there you can pick up with any group you like, from the western-aligned FSA, to the recently betrayed YPG to the Islamic Front, Jabhat al-Nusra and of course ISIS.
Funny then, that you have not already left.