I Sometimes Want to Just Give Up

Have you ever felt so lonely and alone in your life? For the people whom I frequently talk to in here, I probably appear as someone who is jolly, doesn't have any problem in life. No, that's not me. I feel like there is a black hole living inside me that sucks out all my happiness. I'm still not over my father's death even if it has already been 2 years then about a month ago, my grandma died due to breast and lung cancer. My younger brother moved out and now lives in a boarding house near his school. My mom has been in the hospital for 2 months now. It's just me and my other grandma in this big house. Big but empty, lonely house. I always have nightmares that wake me up in the middle of the night. I thought of killing myself to end this pain, to dry these endless tears I've been crying, to get rid of these huge responsibilities on my shoulders. I'm tired. Exhausted. Drained. Empty. I'm not like this before, what happened to me?