Can I get disability for Pernicious Anemia?

My doctor told me yesterday that I was lucky- we almost lost you were his exact words. I was recently diagnosed with Pernicious Anemia- a B12 deficiency. I suffered for 3 long years with debilitating illness that I stopped working full-time and only worked 16 hours a week. I went to see every specialist in the medical field and not one could find anything wrong with me. I was fatigued, shaky, has severe acid reflux (I would throw up after every meal), I was sick all the time, I couldn't make it up the stairs or walk around the house- I was barely taking care of myself- bathing would cause me to faint so I took sink baths. My doctor sent me to a cardiologist because my EKG was off the charts. Finally, after fainting in the grocery store- my doctor took blood work and the results showed my hemoglobin level was 5.9- she gave me a bunch of iron pills and told me to see a hematologist and gastro doc. My gastro doctor told me there was nothing wrong with me six weeks prior, so I didn't go back to her. She had performed 5 procedures already where I had undergone anesthesia and I wasn't interested in going under again- the last time I felt like I was having a heart attack. I contacted the hematologist and couldn't get an appointment for another six weeks. I was dying and no one knew why. Fast forward two weeks, I finally called the gastro doctor who saw me the same day, she insisted that I go the hospital for a blood transfusion- so sick and unable to walk I did. After my lab work, I was told my condition was critical and I was admitted into the hospital. After 2 blood transfusions, they still didn't know why I was so ill. hematologists blood and finally a diagnosis- Pernicious Anemia. I stayed at the hospital for a week and received another transfusion. A visiting nurse came to my house every day for 2 weeks to administer a B12 injection, now I have an injection every week for 3 months- after that once a month for the rest of my life. I have been unable to work- I work in retail, I stand 8 hours a day. I was told I have neurological damage because I went for so long without B12 in my body. I am still very fatigued and unable to stand for long periods of time without feeling faint. My acid reflux is gone, Irritable Bowel Syndrome is gone- but I have pains in my chest and extreme tiredness, even with sleep. I need more time to heal. My problem is, my doctor said I have his permission to be sick but he hasn't responded to my disability claim.