Helping others is a great way to forget your own troubles. Try to avoid alcohol. Many seniors develop alcohol dependence after retirement or loss of a loved one. Alcohol is a depressant and will intensify those feelings of sadness. Watch your finances.
Most seniors are on a fixed income.
Set a budget for gift giving and stick to it. Don't feel guilty if you can't afford to by those grandchildren an expensive gift, its you they will remember not the gifts. Overspending will cause worry over bills after the holidays are over. Don't deny or try to hide your feelings of sadness. Very often just being able to share your feelings with someone can help To help cope with post holiday letdown, spend some time organizing and mounting photographs taken during the holiday.