I can feel the emotion in this piece, which is always the most important part about a poem. I will say that at the end you say it "can't be put into words." I would suggest that you take these feelings and use objects and images as symbols for these emotions. Specific details hit home harder and sometimes get to a deeper understanding.
She understands. She is your sister after all. Seeing you care for her is new. Most people don't, nowadays. And that is why you are so strong. You are so swathed in your own problems, yet you manage to hold regrets about how she might be feeling. You couldn't help what happened. Don't blame yourself. If it is really in your hands to do something, then do it. If you can fix a little bit of that pain, bring her a little bit of happiness to replace it, go for it. You don't have to give her the world. She knows you can't, wouldn't want you to. Wishing will achieve nothing. You need to put your all into action. Make her happy. You will find pleasure like you've never known before, if you love your sister that much. I think she knows. If she doesn't, (which I doubt), seeing this will surely explain?
Im am the one who you look to if you need a shoulder to cry on, but also the person you cross the street to avoid. I am cold hearted and caring. An oxymoron given physical form. more..