I would do things that would help me regain at least a small sense of control. Sure, many things in this situation are out of your control, but what are some things that are within your control? What was that saying? God, grant me the serenity to accept the things I can't change, the courage to change the things I can change, and the wisdom to know the difference.
So what are the things that are within your ability to change? For example, I would start looking for jobs and editing my CV, not because I necessarily want to leave the job, but because it's good to see what's out there and be prepared. If there are good job opportunities, I would submit my resume and see what comes of it. If nothing comes of it, then that's okay, nothing has changed from your current situation, but if you get a job offer that's as good as your current job, then you have the option of choosing a better situation.
It sounds like, in the past, you were not in landline phone service. So maybe when applying for jobs, try to apply for other areas so that you're not stuck in this "dying service".