Be anxious for nothing (don’t be worried or burdened about anything), but in “everything” by prayer and supplication, with thanksgiving, let our requests be made to God; and the peace of God, which surpasses all understanding, will guard your hearts and minds through Christ Jesus; Philippians 4:6&7. 
We show our faith when we thank God, in advance, for answered prayers.  Being thankful helps to relieve us of the burden, as if it’s already done.  Cast your burden on the Lord, and He will sustain you; Psalm 55:22. If the burden is extremely heavy or prolonged, we may need to remind ourselves to keep it cast on the Lord and remain thankful, while waiting.   This brings to mind a “cast” sheep.  This is one that has rolled over and all it’s thin wiggly legs have left the ground.  Since a sheep is naturally top-heavy, and unable to cast off a possibly heavy coat of wool, it can’t roll back over.  In this state it can die, and quite quickly on a hot, sunny day.  A caring shepherd will examine his fields everyday, incase he needs to rescue a fallen one.  If so, he simply rolls it back over and watches it a bit, to make sure it is steady.  God is a loving Shepherd who always has His watchful eye on His children.  He’s so pleased to unburden and steady them, as they trust Him.  The next time you are burdened, cast it over on the Lord, in faith, so it will not cast you down!  His shoulders are big and He is well able to take care of it!