Calming the mind

I am usually a calm person but lately my anxiety is off the roof. A little bit of background. I am a 28 year old female about to end my enlistment in the army and have put my resume out there. But I haven't heard anything back from the government. I am getting really stressed because it feels like i am diving into the unknown and the date of end of contract is really close. Worse case scenario, I will use my GI bill to pay for my rent but that hasn't stopped me from being anxious. Question: Is there something I can do to stop worrying and keep my mind at peace? Do you guys have any advice you can give me which made it easier for you to go through a difficult uncertain time in your life. Also, are there any mantras, or book or anything in the teachings of the Buddha which might help me. Thanks again