You are not responsible for the happiness of your parents, or your sister. They can choose to be happy or not to be happy,it is not your choice.
A total failure? You are not. You are still alive, able to type a prayer request, able to see, able to hear. Your job is not the most important thing in this life. You were looking for a job when you found the one you lost, so you are looking for a job again. What if the Lord has something better for you than "just a job"? You should ask Him what He wants you to do.
The best way to change your circumstances around you and to have the people around you do some changing is found in this verse of the Bible, the Word.
Proverbs 4:20-23 (ASV)
20 My son, attend to my words; Incline thine ear unto my sayings.
21 Let them not depart from thine eyes; Keep them in the midst of thy heart.
22 For they are life unto those that find them, And health to all their flesh.
23 Keep thy heart with all diligence; For out of it are the issues of life.
You, your flesh, your family will all be affected if "you" will make Jesus and God your main focus in life. Read the Word daily, especially the New Testament. Read it, memorize passages, speak passages aloud, mediate on the Words you have read. Sing praise songs, worship the Lord, And love others around you. Love them like Jesus does and says to do. When you do these things the people around you, your family, shall change. Keep your focus on Jesus, the Father, and the Holy Spirit.
In the name of Jesus, I bless you with the life of God