First, I'm so very sorry for your loss. Even though it's been years, I can tell it is still a fresh wound. There are certain people who when they hurt, they feel they have to find someone or something to blame. It sounds like these people are using you as a 'blame cushion'. That is very wrong. I want you to know that. They are wrong to do that!
I am confident that you are making your dad proud by trying to live the best life you can. I hope you are striving to be the very best person you can be. Even though you were young when your dad died, you had enough time for him to show you a lot. How to laugh, how to love, and more. These things are still inside you. THey will never leave. And when you laugh and love and live life to the fullest, you are most definitely doing your dad proud. I'm so proud of you for going back to get your GED. That shows strength, courage, patience, and endurance. Way to go. There are many who let fear of failure and whatever troubles they are going through prevent them from obtaining their GED. Keep at it. Keep working hard at it and you will succeed. If these people continue to abuse you by blaming and pointing fingers, you might consider putting some distance between yourself and them. If a person isn't helping build you up as a happy, strong, confident person, then they are tearing you down. And nobody needs that kind of person in their life. There are so many people out there that need good friends and family. A family isn't just people of blood. A family is where you find your heart, your thoughts, going to. You can create a healthy family by finding good people to spend your time around. You deserve that. Your dad would probably agree! Trying to end things through suicide is not the answer and I think you know that already. I don't think you want to do that because you are here, asking for advice, seeking words of encouragement to keep going. You definitely sound like you are going through some depression and maybe some post tramatic stress issues, likely due to your dad's death. Consider getting involved in a support group that deals with grief/death. Talk to a pastor or a spiritual friend/mentor. You deserve life! You deserve the best kind of life!