How to fix net::ERR_CONNECTION_RESET when uploading files from javascript to php?

Question

So I've been struggling with this for the past few hours and couldn't find a working solution anywhere.

I've made a multiple file uploader in my website. For a long time it worked well or at least I thought it does. Recently I tryed uploading 3 images (total size 16MB) and at some point it displays this in console:

 Failed to load resource: net::ERR_CONNECTION_RESET

This is my upload source:

    $("#submitform").click(function() {
        var h = document.getElementById("filelist");
        if (h.files.length < 1)
                return;

        $("#state").css("display", "block");
        var xhr = new XMLHttpRequest()

        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                $("#state").css("display", "none");
                if (xhr.responseText == "")
                    alert("Files uploaded sucessfully.");
                else
                    alert("Failed to upload files: \n" + xhr.responseText);
                location.reload();
            }
        };
        xhr.upload.addEventListener("progress", function(e) {
            var pc = parseInt(e.loaded / e.total * 100);
            $("#precentage").html(pc + "%");
        }, false);

        xhr.open("POST", "uploadImages.php", true);
        var data = new FormData();

        var j = 0;
        for (i = 0; i < h.files.length; i++) {
            if ($('#use' + i).val() == 1) {
                data.append("image" + j, h.files[i]);
                j++;
            }
        }

        xhr.send(data);
    });

and uploadImages.php does some basic algorithms that work whenever I try to upload a single image.

My php.ini looks like this:

 file_uploads = On 
 post_max_size = 500M 
 upload_max_filesize = 500M
 curl.cainfo = "/home/accountname/php/cacert.pem"

I've tryed adding cacert.pem but it doesn't fix anything. I'm using godaddy's linux starter pack to host my website, if that matters.