My Dad keeps threatening me, how do I handle this maturely?

Yea, the yelling probably really helps...not. Your dad does want what is best for you and he is probably just stressing. Be part of the solution, not the problem. So before he can ask you how the job hunting is going, tell what you have accomplished. Ask him for input regarding if he has any ideas on where you can apply or if he knows any friends who might know. This will at least show him you have received the message and trying to take control. Don't get discouraged, it will get better. Good luck.