There may be a way to convert the integer generated by GetPlayerHealth into a string usable with the SetMessage function so you don't literally have to write it out 100 times. I did some research, but I'm not all that familiar with complicated programming, so you can take a look yourself:
string convertInt(int number)
{
   stringstream ss;//create a stringstream
   ss << number;//add number to the stream
   return ss.str();//return a string with the contents of the stream
} 
string convertInt(int number)
{
    if (number == 0)
        return "0";
    string temp="";
    string returnvalue="";
    while (number>0)
    {
        temp+=number%10+48;
        number/=10;
    }
    for (int i=0;i<temp.length();i++)
        returnvalue+=temp[temp.length()-i-1];
    return returnvalue;
}