How can i be happy when this world is so messed up?

Hi, im a 30 year old male who been through same as you and some. I started out at a young age using and drinking. I burried atleast 5 really close friends b4 I graduated high school. I lost the woman I loved for 12 years and my 3 children due to my lifestyle. (not to death but she left and took kids). I was soo addicted to drugs that I hated to attempt to get out of bed everyday without knowing I had a high waiting on me. The life I was living was a sick, evil, perverted life in which landed me in jail for a total of 8 months and then I got released on Community Corrections for 8 years. (Same as doing a prison sentence on the outside, as much as a speeding ticket=jail). Somewhere in the midst of all of this I decided that this way of living is not good at all for me or anyone. I remember feeling hopeless one night before going to bed and I just hit my knees in tears and cried out to God to fix my life his way, not my way. (I really meant this) From that day to present, He has given me a peace and hope in my heart that only he can shake. If I could change anything about my past, I wouldn't change a thing. If it wasn't for me going through what I went through I do not believe that I would be who I am today. I wouldn't be able to relate to others like you. I did walk that road and I overcame it when I asked God for his help. Hold your head up and stand firm on the little ground that you have left.