Earlier today I started up my Xbox 360 (It's fairly old now) and I was welcomed by the default Xbox home, without being signed in to my profile, so I went to sign in to my profile when I noticed it had disappeared, so I looked in storage and it said the profile was corrupted, so I re-downloaded my profile, and it all went pretty well, when I decided to launch a game though, I encountered a lot of problems. First problem was when I tried to launch GTA V, where it asked me to do the 8gb install, despite the fact the fact I already have it installed. proceeding on I tried an array of different games, all with similar problems, causing the games to become unplayable and making my console almost obsolete.
So what I'm asking here is:
1. What caused the corruption in the first place?
2. Are the in-game problems related to the fact my profile was corrupted?
3. How do I go about resolving this problem?
Thanks in advance to anybody who is willing to help.