is my boss asking too much?

this is sort of long so please bear with me, i promise it is all relevant to the end question. I had called out sick from my job once before due to my sons being sick, when i went back to work the next day my boss called me to his office and told me that if i called out sick one more time that he would cut my hours in half from 40 down to 20, unless that is i could provide a doctors note (he does not offer ANY health insurance). okay moving along. . . about 2 weeks ago i had what i thought to be an ear infection so i called out sick and went to see a doctor at my local health center that evening. the next day i was scheduled to be at work at 5pm, around 1pm i called the manager (not the boss) and told him that i was still sick but my doctors note was only dated for the previous day, he heard me coughing on the phone and told me that i sounded horrible i should just take that day off too and not worry about showing up. the next day i was still sick but went to work where upon before starting my shift the manager spoke to me and determined that i was still sick and in no condition to be working (i work in food service), this went on for a few more days until finally the owner of the business told me the day before i was scheduled to have a day off that if i was still sick on my day off to call him and take the rest of the week off to rest that it would be easier for him to cover my shifts for an entire week versus day to day, which i did because i was indeed still sick. that same day (it was by then a tuesday all this having started the previou thursday) i called my doctors office and was given the next available appointment which was that friday morning to be seen since i was not getting any better. i went to see the doctor and was diagnosed with bronchitis and put on an antibiotic, i told her about the situation with the note how it only covered the one days absence and that i had been out for over a week by then. the doctor wrote me a note saying i would be able to resume working othe following monday and put in the additional comments section to please excuse my absences from the prior week that i was indeed sick those days but did not go into detail as to what the exact illness was that i had been suffering from. that night i brought my note to my boss and told him the situation about the bronchitis and antibiotics and such, where upon he told me that he needed a note from my doctor stating specifics i.e. my exact condition, the dates that i was ill AND he said he needed the doctor to sign the note more legibly. that was a friday evening so i called my doctor back and spoke with a nurse this monday and told her the situation she told me that in order for them to write a note with my specific condition i would need to sign a medical release form making it possible for them to tell my boss anything he wants to know. i told my boss this and that i was completely uncomfortable signing said form especially when i gave him a note from my doctors office on letterhead saying i was sick and the dates and all that nonsense just not exactaly what i had bee sick with he insists that i need to do this or i will lose my job and it just makes me feel uneasy to think of him having access to all of my medical records. i feel that the note my doctor gave me should be sufficient to serve the purpose he wants it to serve which is to say that yes i was ill and unable to work those days and that yes i am able to come back into the work place with no risk to the customers. is it okay for me to refuse to sign a medical release form?, and more importantly is it okay for him to demand that i do so or not return to my job

[able1]

You can refuse and have a medical opinion given in writing about your status etc.--you cannot be fired for that.