Learn a new language. PHP (while not entirely garbage in its modern form, though based on your post I'm guessing you're not using it in a very modern way) has a stigma insofar as I (for one) assume someone that has only used PHP is not likely to ramp up quickly because they lack intellectual curiosity.
Honestly, when I'm looking at resumes, I immediately assume anyone that only has experience in one language is at best a junior level engineer even if they have 10 years of experience.
I'd recommend Python or Java. .NET is also an option. Learn them in your spare time (hell, even use them at work, no one will notice) and make sure you build something substantial before you put it on your resume.
There is a truth here. A lot of companies build their first system in php. IME no one hires developers to build their second system or third in php, except maybe Facebook.
Honestly, when I'm looking at resumes, I immediately assume anyone that only has experience in one language is at best a junior level engineer even if they have 10 years of experience.
I'd recommend Python or Java. .NET is also an option. Learn them in your spare time (hell, even use them at work, no one will notice) and make sure you build something substantial before you put it on your resume.