I design amazing accessible user experience (UX) for websites and apps. I try to have my designs reach an AA WCAG rating. I help craft UX for a few big brands and currtly Lead UX designer at H&M.
I would suggest hiring an expert. They can help uncover these potential problems allowing you to focus on business.
But if you do prefer to do it yourself, I would recommend running a few usability testing sessions, these can really help uncover the core usability problems. This allowing you tweak your design to make it work better with your users.