my letter for the insurance company

can some one tell me what all i should include in my letter. mu
insurance at this time is healthy families medicaid. i have a letter
already but not sure if i have included everything and how short
should it be. I have had my best friend and my father in law have the
same done with same insurance. but i just know because its me that it
will require more lol that is just my luck. i have already been
through 2 other drs as the decided after making me weight that they
werent going to take my insurace. so now i have found another dr that
has a good rep that is willing to take it. so i am starting all over
again and i have done my letter and my diet history so that it is
done, and i go to this dr.'s seminar on the 6th. 17 days away lol and
counting. thanks for the help
Tracey