What do I do about this payday loan??

Most of the reputable companies will work with you and let you make 2 payments if you call them before the payment is due. 8)

I took it out with mycashnow.com I live in Maine and they are saying they will take me to court and everything else. I just filed bankrupsy and have nothing to my name to give. I am really up the creek and they are saying all kinds of crazy stuff.

Chances are that they probably aren't licensed to do business in Maine, but you can confirm this by using the Google search function you can find on the forums. If not, relax. They are blowing smoke you-know-where.
Since you are also filing bankruptcy, depending on what chapter you are doing, I would check with your attorney to see if they can be included in it. You also need to educate yourself on Maine state laws for PDL's. Remember, you owe the principal (what you originally borrowed) plus LEGAL interest on it. And in no state is interest at 3000 percent or whatever it usually is for a PDL legal.
You also need to put a block on any debits that they try and make in your bank account--and possibly get a new account if you can,

PDL's are illegal in Main! So all you need to pay them is the money your borrowed from them and you need to send them a letter stating this. www.paydayloaninfo.org and click your state for your states laws and where to file a complaint. They cannot come after you because they should not have lent it to you in the first place!

Yes, they will say anything they can to intimidate you into paying them more money. Don't let these shysters scare you. They are operating illegally. Make sure you file the complaint. If we all file complaints with our attorney generals eventually we will get these companies shut down that are loaning illegally and preying on desperate people.