how can I fix my Samsung Galaxy Y GT-S5360? All of my applications are forcing to close such as its home, messaging, play store services and others.I can't make changes or even open application drawer or home.I can only open my contacts and make a call.
As your device is stock, something likely became corrupted in the file system and a factory reset is about your only option. You will lose all your data, unless your phone will still communicate with a computer. If so, you may be able to use Kies to back up your data from the phone first. 

To factory reset:


Enter recovery

Power off the device. Press and hold the volume up key and the home button while powering up the phone. Hold these keys until the Android recovery screen appears. 
Use your volume keys to navigate to wipe cache partition. Press the power button to choose this option. This won't destroy your data and may allow it to boot normally. Select reboot system with the volume keys and press power. It will reboot and hopefully work. If it doesn't, follow the next step. 
Enter recovery mode as described above. Select "wipe data/factory reset" with the volume keys and press power to select it. THIS WILL DELETE ALL DATA FROM YOUR DEVICE. BE SURE YOU BACKED UP ANYTHING IMPORTANT. Now reboot the system and it should be back to stock with everything working again. 
If you used kies to backup your data, now you can restore it.