Trust not in yourself or in any of your devices (mind, bodily impulses, thoughts, and most definitely not the heart), even in matters you think may be small, but lean on the Lord for everything and put all of your trust in Him:
Trust in the LORD with all your heart, and lean not on your own understanding;
In all your ways acknowledge Him, and He shall direct your paths. (Proverbs 3:5-6 NKJV)
Trusting in yourself is like walking through a dark cave with only the candlelight as your guide. Some passages you will see, many you will miss; some sharp edges you can avoid, others you will run into blindly. Trust in the Lord wholeheartedly; He will shine the sun throughout the entire cave, illuminating every crevice such that darkness could not even hide within the smallest cracks.
A man that chooses to trust in his own devices in even the slightest way is also like a man digging a hole searching for water. He may find a little water, but only for a short while, for he will surely have to dig again as soon as the last hole dries up. This he will continue to do all of his life. Meanwhile, a river flows endlessly right behind him, merely a few yards away, but he does not see it because his stubbornness has taken him.
Let the Lord lead you, lest you’d like to find yourself digging for a lifetime for only a few drops of water, when you could have had an instant and endless supply, no digging required.