First sentence: The girl didn't care about the repercussions of being with a guy who was behind bars for years. Your second sentence is a little more difficult for me. I'm not sure that 'stagnant' even belongs there. 'Stagnant', when referring to one's circumstances or life, usually refers to a lack of excitement. That life is no longer enjoyable as it has become routine. So, if I were to remove it, something like this: "Today I felt stressed about my life, for I cannot find someone with whom to express my feelings about the passing of my grandmother." I made an assumption there that your grandmother had passed away. For your third sentence, I will try my best as I think I know what you are trying for here: "The pursuit of endless, futile endeavors is wearying and tiresome. All that you can do is to make your best efforts to achieve what you can in the time you have, even if it is laborious to do so." I changed that quite a bit, so I hope that properly expresses what you are trying to achieve. By the way, I love the line "The pursuit of endless, futile endeavors...". It's very poetic!