Russian Tortoise in very poor condition?

I recently acquired a russian tortoise from a friend of a friend of a family member. They said he was in bad condition but i had no idea it would be this bad. Both of his eyes are swoolen shut, he cant see and won't eat, I'm not sure he can even open his mouth enough to eat.I've got him in a big kiddy pool with one side around 91 and the other around 72 degrees with around 50% humidity. Is there any way I can make him a happy healthy tortoise? He is in terrible condition, and i am worried keeping him alive is only causing him more pain.I feel if he could just get his eyes open he would be able to get on the right track to recovery. If putting him to rest is the only option I am willing to do so as seeing him in this condition makes me feel sick and i would hate to see him keep suffering if he has no chance of survival. I have been letting him soak in warm water as often as I can to try and help his dry skin and hopefully help his eyes open. Any help is highly appreciated. Thank you