I have been diagnosed- currently- with schizoaffective disorder and adhd but sometimes I wonder if these conditions are even real and if mental illness is instead just something that weak people claim when life gets too hard (not to offend anyone- its just something my mind asks)

My last therapist asked how I can dismiss my mental illness when I experience such severe symptoms sometimes (like hallucinations- she said those are fairly objective “proof”) but I just dont know! Maybe I just am imagining things. Maybe I just am a weak person who is struggling to like- like- be like everyone else. Maybe Im just not trying hard enough. I just. Maybe Im paying my symptoms too much attention and if I figured out a way to ignore them and focus on other things maybe id realize im not sick and am just like everyone else. Maybe its just not REAL anymore than I make it be real. 

What if its all just in our heads? What if its all just MY choice? How could I live with myself knowing that Im the one choosing to be sick