SQLSTATE[42000] [1226] User has exceeded the 'max_user_connections' resource - mysql

Question

in my website I am trying to make asynchronous calls to my database with jquery ajax function at least 100 times at the same time in a for loop and after some queries (definitely more than 30) I get the error:
SQLSTATE[42000] [1226] User '***' has exceeded the
'max_user_connections' resource (current value: 30)
but I am using a shared hosting and they say I/they cannot change the max_user_connections value to a higher number.
Now, I have no idea how to solve this problem. Is there anyone who knows a way? Thank you.
Edit: I have a website for classification of species/taxonomy and I want to show this in a sunburst chart but there are more than 65K species and it is hard to draw all chart. To achieve this, I made this chart clickable and when an user clicks, new elements are drawn by the response of ajax call.
For simplification, I do not include the lines that I define the variables.
JavaScript:
$.when(info(domain,name)).done((response)=>{
try {
layer_info = jQuery.parseJSON(response)
}catch (error) {
console.log(response)
console.log(error)
}
for (let i = 0; i < layer_info.size; i++) {
$.when(info(child_domain,child_name)).done((resp)=>{
try {
child_info = jQuery.parseJSON(resp)
} catch (e) {
console.log(resp) // I get mentioned error from info.php on console from this line.
console.log(e)
}
})
}
})
Function info makes the ajax call and returns the response.
function info(b,i){
return $.ajax({
url: "info.php",
method:"POST",
data:{domain:b,name:i},
dataType: "text",
})
}
info.php:
try{
$timezone = "+3:00";
$db=new PDO('mysql:host=localhost;port=3306;dbname=***;charset=utf8','***', '***');
$db->exec("SET time_zone = '{$timezone}'");
$db->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
}catch(PDOException $e){
echo $e->getMessage(); // this line generates the error
}
try{
$name = $_POST["name"];
$domain = $_POST["domain"];
$count_query = $db->prepare("SELECT COUNT(*) FROM table WHERE $domain=?");
$count_query->execute(array($name));
$count_result = $count_query->fetchColumn();
$query = $db->prepare("SELECT * FROM table WHERE $domain=? GROUP BY $sub");
$query->execute(array($name));
while($results = $query->fetch(PDO::FETCH_ASSOC)){
array_push($nodes,$results);
}
$data['spec_size'] = $count_result;
$data["size"] = count($nodes);
$data["childs"] = $nodes;
echo json_encode($data);
}catch (\Throwable $th) {
echo $th;
}