Phone is stuck on "Searching..."

Hi there! I've had service with Straight Talk for about 4 years and haven't had any issues until now. On Saturday, my phone started losing signal pretty frequently but sporadically. Service would come in and out. Starting on Wednesday, however, I've been unable to find service at all. My iPhone has been stuck with "Searching..." for service for over 24 hours. The problem started originally at my home in Atlanta, but I've since traveled up to New York City for business and still have no service. I really need to use my phone while away this weekend. Is there any way to fix this issue? Thanks!