The best you can do now if focus on recovering from the depression and the abuse. Accept a helping hand when offered... consider such offerings to be a stepping stone to the happiness you're wanting.
Just keep in mind that you are PROGRESSING in your improvements... though this progress may be slow... it isn't stopping --- which is a good thing. One step at a time... one small triumph after another.. and YOU WILL MAKE IT. Happiness will be yours again, rest assured.
Be thankful for all the help you have received... try to not dwell on what may not have turned out as you had hoped (this will only fuel the depression)... keep a schedule and try to stay busy/preoccupied with other things... so your mind can't wonder and so you will feel useful.
This will take time... but you are getting closer to regaining happiness.
"The weakest soul, knowing its own weakness, and believing this truth that strength can only be developed by effort and practice, will, thus believing, at once begin to exert itself, and, adding effort to effort, patience to patience, and strength to strength, will never cease to develop, and will at last grow divinely strong."
- James Allen