Forget about what happened before, start fresh now...
Some folks will disagree with my suggestions, but tough tiddliwinks.
How to set goals, the quick version:
4. Don't be too rigid. Things go wrong. Adjust and move on. Rigid thinking is what puts goals on the shelf for another year. Relax a bit and if something goes wrong, dust yourself off, adjust and keep plodding along. You'll make it!