How to handle multi communications (I2C SPI UART) in single program of arduino

I am doing one project using ARDUINO UNO, which is ADC(ADS1115, 3 analog inputs) data and GPS(NEO-6M-0-001) data to store in microSD card.

Here the the GPS contains UART(Tx, Rx) communication, SD card contains SPI communication and ADS1115 contains I2C communication.

Here when i'm connected GPS and Sd card, The GPS data is stored in SD card and Like this when i'm connecting ADS1115 and SD card the data is stored in SD card 

But the problem is while i'm connecting all (GPS, ADS1115, SD card) at a time it is not storing data in sd card. (Some one told me that is using of different communications in single program)

how to solve this issue ?

i tagged my code also please find it. 
<CODE>

#include <TinyGPS++.h>                                  // Tiny GPS Plus Library
#include <SoftwareSerial.h>                             // Software Serial Library so we can use other Pins for communication with the GPS module
TinyGPSPlus gps;                                        // Create an Instance of the TinyGPS++ object called gps
static const uint32_t GPSBaud = 9600;
#include <SPI.h>
#include <SD.h>
#include <Wire.h>
#include <Adafruit_ADS1015.h>

Adafruit_ADS1115 ads;  /* Use this for the 16-bit version */

SoftwareSerial ss(6, 5);                                // The serial connection to the GPS device

void setup()
{
  Serial.begin(9600);                                 // Update display
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }
  //delay(500);                                          // Pause in milli seconds
  ss.begin(GPSBaud);                                    // Set Software Serial Comm Speed to 9600
  // set up the LCD's number of columns and rows:
  // lcd.begin(16, 2);
  // lcd.print("Flux gate magnetometer");
  if (!SD.begin(4)) {
    //   lcd.print("sd card initialization failed");
    Serial.println("Card failed, or not present");
    return;
  }
  ads.begin();

}
void loop()
{
  /////////////////
  float flat = gps.location.lat();
  float  flon = gps.location.lng();
  /////////////////
  int16_t adc0, adc1, adc2;
  float xdir, ydir, zdir, Tfield;
  /////////////////
  adc0 = ads.readADC_SingleEnded(0);
  adc1 = ads.readADC_SingleEnded(1);
  adc2 = ads.readADC_SingleEnded(2);
  xdir = adc0 * (0.1875 / 1000) / 0.000025;
  ydir = adc1 * (0.1875 / 1000) / 0.000025;
  zdir = adc2 * (0.1875 / 1000) / 0.000025;
  Tfield = sqrt(sq(adc0 * (0.1875 / 1000)) + sq(adc1 * (0.1875 / 1000)) + sq(adc2 * (0.1875 / 1000))) / 0.000025;
  //////////////////
  File myFile;
  /////////////////////
  while (ss.available() > 0) {
    gps.encode(ss.read());
  }
  if (gps.location.isUpdated()) {
    myFile = SD.open("test2.txt", FILE_WRITE);
    if (myFile) {
      myFile.print(F("  Date/Time: "));
      // lcd.print(F("  Date/Time: "));
      myFile.print(gps.date.month());
      myFile.print(F("/"));
      myFile.print(gps.date.day());
      myFile.print(F("/"));
      myFile.print(gps.date.year());
      myFile.print(F("/"));
      if (gps.time.isValid()) {
        if (gps.time.hour() < 10) Serial.print(F("0"));
        myFile.print(gps.time.hour());
        myFile.print(F(":"));
        if (gps.time.minute() < 10) Serial.print(F("0"));
        myFile.print(gps.time.minute());
        myFile.print(F(":"));
        if (gps.time.second() < 10) Serial.print(F("0"));
        myFile.print(gps.time.second());
        myFile.print(F(":"));
        if (gps.time.centisecond() < 10) Serial.print(F("0"));
        myFile.println(gps.time.centisecond());
        myFile.print(F(" "));
        myFile.print("Latitude  : ");
        myFile.println(flat, 6);
        myFile.print(F(" "));
        myFile.print("Longitude : ");
        myFile.println(flon, 6);
        myFile.print(F(" "));
        myFile.print("fieldX in nT: ");  myFile.println(xdir);
        myFile.print(F(" "));
        myFile.print("fieldY in nT: ");  myFile.println(ydir);
        myFile.print(F(" "));
        myFile.print("fieldZ in nT: ");  myFile.println(zdir);
        myFile.print(F(" "));
        myFile.print("Total field in nT: ");  myFile.println(Tfield);

      }
    }
    myFile.close();
  }

  myFile = SD.open("test2.txt");
  if (myFile) {
    // read from the file until there's nothing else in it:
    if (myFile.available()) {
      Serial.write(myFile.read());
    }
    // close the file:
    myFile.close();
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening test1.txt");
  }
}