Hey man, just be cool and keep at it. Whatever you feel like you might be weaker on or want to get better at, go buy some scrap and just do that all day. Just hammer the technique until it's second nature.
There are things out there you'll be fantastic at right out of the gate and other things you're going to need a lot of work on and help with but eventually you'll be looking ta your work trying to figure out how you had such a hard time with it in the first place and offering help for people who have the same issue in the future.
Just keep at it and eventually you'll be flying through it.
To answer your question more directly - I have a heavy bag (which I highly recommend). Whenever something gets be frustrated or discouraged I tee off on it for half an hour and that gets out off of my frustrations enough to where I can go right back to what I was doing.
Give it a shot.