Feeling so sad not being employed because of my mental illness

I’m feeling down because when I was in hospital I was offered this little cleaning job which I turned Down . now my meds side effects have changed  and I’m starting to feel better I messaged the lady bout the cleaning job got told I had the job and then was sent over all the medical questionnaire pack and I was honest wrote down I suffer with mental illnesses and what’s meds I’m on and then all of a sudden the admin emails me telling me they have changed there mines no reason . 

I know that them seeing I have a nurse and the meds I’m on put them off it just makes me so sad . I have always been pro telling other disabled people’s you should tell employers upfront about your disability but the next job I go for that’s if I do apply for any more local cleaning jobs I won’t be mentioning my illness at all I’m feeling so down just feel laughed at by these people .