[Q] Some major problems I am facing with Samsung Galaxy Y

About a week ago I rooted my Samsung Galaxy Y CDMA (SCH-i509). I used it for 2-3 days. Since I needed a more external memory, I exchanged my phone's sdcard with my father's sdcard which was 16 gb. I exchanged all the data using a computer but then, since almost all apps had been uninstalled, I decided to reset my phone. So I went into recovery mode and reset it. Then I started getting some problems. First, I noticed that the mobile wasn't getting locked. Pressing the power button just put the screen asleep. Then I noticed that the home button wasn't working. I could use it to make screen awake and take screenshots, but otherwise it just didn't do anything. Then I realised that all the calls were getting auto rejected, but it ala showed them as missed calls. I checked the settings but everything was alright. There were also many other problems like I can't watch any videos on my sdcard. I thought that while transferring the data, the videos might have got broken. But then I recorded a video and couldn't watch it too. Then I went to the browser and still couldn't stream videos but I could still watch videos on YouTube. I am also facing loads of other problems. Can someone please tell me why this is happening and how to tackle these problems?