Forgive me for being naive, but I'm sure it won't be as bad as what you're thinking it will be, if you decide to go that is.
Keep in mind I don't know anything about the Russian army, but I'm working on the principal that nothing is, usually as bad as you think.
From my own personal experiences (that has nothing to do with the Russian army I can assure you), I have usually found that running away from
anything has never helped, I've either felt chased by it my entire life or it has finally caught up to me.
The way I see it, is you suck it up and get it over with or you run away and look behind your shoulder for the rest of your life, If you do get out of it with legit reasons then you just got lucky.
If it was me and I was in your position then I'd suck it up and serve but I'm in a different position to you as I feel confident enough to defend myself, physically and mentally. Maybe you can take a good point from this with the fact that when you come out of the army, you'll be confident enough to deal with any situation life will throw at you.
From your recent threads on this site it seems you really don't know which way life is going to take you, you're stuck with your nan and working a job that you don't seem to enjoy, maybe the army is the thing that will give you a kick up the arse to finally get you out of this rut.
I've suffered with depression for the past few years (but what feels like my whole life) and I can tell you that your way of thinking is a fast track to being stuck on medication. I ran away from a lot and did a lot of things I regret and it all caught up with me. I beat myself up about everything, thought the worst of everyone and it sent me down on a spiral and onto a path that I'm still barely recovering from.
It could be the best thing that ever happened to you, something that made you a better person. Or it could be a little bump in the road, a bad experience with another life lesson learned. Just don't ever regret not knowing which one it would be.