In Matt 6:34, jesus tells His audience to not worry about tomorrow for it has enough worries for itself.  Here is you reality, everyday that you live you will be faced with a thousand choices and situations.  Each one can be faced with faith or worry.  You can fear the future or embrace it.  Change will always happen and you must be ready for it.  You ask the question, How do I do that?  Well you can trust God that He will help you face each new situation with His help.  God knows the end from the brginning, that means He already has a solution.  What you need to do is trust Him to guide you through each situation and seek first His kingdom and then all things will be added unto you.  God will show you what to do, how to do it, why you should do it, where you can go to get all you need to meet it and who you can sk for help.  God is there with you all the time.  He will never leave or forsake you.  So you need never fear the future but trust the Lord for the victory.  Don’t borrow trouble for tomorrow.  So trust the Lord and don’t worry be happy.