As Syed Asif Iqbal said remove
myReader.NextResult();
after removing this you can get all record at a time.
For your second question, read all the columns for a specific "fullname" you can write linq:
DataTable dt = new DataTable();
dt.Load(myReader );
var result = (from m in dt.AsEnumerable()
where m.Field<string>("fullname") == "Name"
select m).ToList();