If you are looking for a last-minute idea, I have a few suggestions.
I found the following article at a local office of Catholic Charities. Going on the premise "nature abhors a vacuum", it offers up (no pun intended) a wealth of things upon which to sacrifice and to replace that void:
Lent should be more than a time of fasting. It should also be a joyous season of feasting. Lent is a time to fast from certain things and to feast on others. It is a season in which we should--
Fast from judging others; feast on the Christ dwelling within them.As we strive to live holier lives, these are things to treasure in our own hearts.
Fast from emphasis on differences; feast on the unity of all life.
Fast from apparent darkness; feast on the reality of light.
Fast from thoughts of illness; feast on the healing power of God.
Fast from words that polute; feast on phrases that purify.
Fast from discontent; feast on gratitude.
Fast from anger; feast on patience.
Fast from pessimism; feast on optimism.
Fast from worry; feast on divine order.
Fast from complaining; feast on appreciation.
Fast from negatives; feast on affirmatives.
Fast from unrelenting pressures; feast on unceasing prayer.
Fast from hostility; feast on non-resistance.
Fast from bitterness; feast on forgiveness.
Fast from self-concern; feast on compassion for others.
Fast from personal anxiety; feast on eternal Truth.
Fast from discouragement; feast on hope.
Fast from facts that depress; feast on verities that uplift.
Fast from lethargy; feast on enthusiasm.
Fast from suspicion; feast on truth.
Fast from thought that weaken; feast on promises that inspire.
Fast from shadows of sorrow; feast on the sunlight of serenity.
Fast from idle gossip; feast on purposeful silence.
Fast from problems that overwhelm; feast on prayer that undergirds.
William Arthur Ward