Here are 2 do not's and 2 do's.
1) Do not think about food and drink more than is absolutely necessary.
2) Do not set a target date or weight.
3) Do eat a little less and drink less alcohol than you were consuming.
4) Do take a bit more exercise each day until you reach a workable amount.
Remember: a chocolate bar gives enjoyment for a few seconds; being slimmer will give pleasure for life.