Try

Take a breather.
Once you start crying about the small stuff, the bigger things will take you down in no time, man. Imagine a giant boulder rolling at you at top speed and you've yet to fix the shingles in fear of falling.
Go outside and look around.
Count ten people. Count ten more people. I can bet any amount of money that 21 out of those 20 people have bigger problems then you'll probably ever face. If every little thing confuses the fuck out of you, then what hope do you really have at taking any risks or taking any blows?
None.
So just take it in. Learn to just go with the flow. Learn to understand problems come and go, and more often than not, someone else in the world has been in your shoes before. Stop living with "should haves" and try out "will do's". Just try it.

They really go a long way.