Hi,
We are the team of PHP experts. Our skills include HTML5, CSS3, jquery/javascript, PHP/Mysql, wordpress, joomla, magento etc...
Please share your website URL, so we can check that why your website is loading slow on mobile, we might need to do some CSS customization or something else. It might be 1 or 2 days of task, but we can estimate the same after checking website link.
Looking forward to hear from you soon.
Thanks