Something I would highly recommend you to do is seek out an expert I your area of research (there would be someone) and contact them. Many academics are open to

Something I would highly recommend you to do is seek out an expert I your area of research (there would be someone) and contact them. Many academics are open to discuss ideas, work related to their research etc.. This might give you valuable feedback from someone who understands your work. Now from your post it sounds like you don't work in the natural sciences (apologies if I assumed wrong) so you might not have publications (in many natural sciences it's very common to have multiple publications before the defence, in many humanities the thesis is the publication), if you don't be prepared to send that person some condensed work (they likely don't have time to read a whole thesis) or if you have a publication. However only do that after starting a dialogue and after they have agreed to look at some of your work.