When you have the Lord Jesus in your heart you can remain in a state of joy and peace!  These things are not dependent upon your circumstances.  Feelings come and go but the Word of God never changes.  And His joy and peace are better then anything the world has to offer.

"Don't drink too much wine. That cheapens your life. Drink the Spirit of God, huge draughts of him. Sing hymns instead of drinking songs! Sing songs from your heart to Christ. Sing praises over everything, any excuse for a song to God the Father in the name of our Master, Jesus Christ." Ephesians 5:18-20 The Message Bible

You don't need to look for fun where the world looks for fun.  You have the Author of all fun living inside of you.  You can draw from the well of the Spirit of God within you as you sing songs from your heart to the Lord.  As you worship and praise Him the joy that fills your heart is beyond any 'high' the world can offer. 

Many times when you're feeling good you may fear that it won't last.  But God didn't say anything about His joy being seasonal!  If you have the Spirit of God with you then you always have access to His love, joy, peace, goodness, gentleness, meekness, self-control, patience and faith.

"You will show me the way of life,  granting me the joy of your presence
and the pleasures of living with you forever."  Psalm 16:11, NLT

In the presence of God is joy.  When He is with you then you have His joy with you all the time!  You don't have to lose it when your circumstances change.  You don't have to lose it because you get tired.  You don't have to lose it because someone said something mean to you.  

"Rejoice evermore...In everything give thanks: for this is the will of God.." 1 Thessalonians 5:16-18

He wouldn't tell us to rejoice and give thanks all the time if it wasn't something we could do.  Keep on rejoicing!  

God Bless you and have a great day!