How do I avoid bitterness over being single?

Philippians 2:4Don’t look out only for your own interests, but take an interest in others, too.

Hebrews 12:15Look after each other so that none of you fails to receive the grace of God. Watch out that no poisonous root of bitterness grows up to trouble you, corrupting many.

God tells us to look out for others, thus avoiding the tendency to focus too much on our own needs. We should get involved with groups where we feel safe sharing our feelings and having people support and pray for us.