"Trust in the Lord..." Why is it so hard?

Sometimes, I feel like giving up. I feel like giving up on my life, my way of living, my friends and family... I just feel like it doesn't work anymore! Like if I tried to do anything harder than breathing, I'd just fail. I say one thing, and it comes out like poisonous, cruel words, when all I wanted to do was talk. Something might go wrong around the house or with the car, and all I want to do is worry and worry about it. Or things just generally seem to by ganging up against my. All I want to do is be messed up and worried about them. All I want to do is be mad.
One of my favorite verses is Proverbs 3:5-6:

"Trust in the LORD with all your heart
and lean not on your own understanding;
in all your ways acknowledge Him,
and He will make your paths straight."

My parents just got me a beautiful bookmark that has that verse on it. I didn't realize it till then, but that really is one of my favorite verses. But it is one that I find incredibly hard to follow! Those times when I just say the wrong thing; that is when I trust in my own understanding. And the times when things break or go wrong around me; that is when I don't trust in Him. And the times where the whole day seems to be going wrong, from start to finish; that is when I don't acknowledge and trust in Him. All of these times, I almost enjoy doing what hurts me more. Today, there was a minor problem with the car, and I immediately started to worry. And then He nudged me, reminding me that I need to trust in Him, and be ok with the situation. I was so happy after I put the situation in His hands. It really does feel amazingly great! But what about the rest of those times? Those little times when all I can do in a situation is either worry or put my trust in Him, I find it incredibly easy to do. But what about when I say something that I didn't mean to? I don't ever, at those times, want to lean on His understanding! But how great would that be if I could just say the good things He gives me to say. And what about those times when I just want to have a pity-party? I don't acknowledge Him! But how peaceful it would be to know that He was always taking care of me, even when things are going wrong. To acknowledge that He is all powerful, all seeing, all knowing and loving all!
It's wonderful that God finishes off those two verses with, "and He will make your paths straight." He does give something in return for trusting in Him! I pray that I keep my trust and my understanding and my thoughts set on Him!

Shalom