Xbox 360 won't load home screen

My Xbox 360 was having trouble getting past the Xbox 360 screen so I turned it off and on a few times. I removed the hard drive (which I recently bought, but have been using for a week).i turned it on again and it turned on so I inserted the hard drive again. When I turned it on this time it said it needed to update. I updated and then it signed me out of Xbox live. When I went to sign back in all of my gamer tags were gone. I redownloaded my gamer tag to my Xbox and went to play my favorite game only to see that all my progress was lost. I thought that maybe if I turned off the Xbox and removed the hard drive again then maybe it would be somewhere on the xbox's memory. When I went to turn it back on it had the same problem of not going past the Xbox 360 screen. I turned it off again and looked up the troubleshoot. I opened the disc, removed power cord, turned it back on and it went to the Xbox 360 screen and did nothing. I turned it off, replaced the hard drive and did same trouble shoot. Now it made it past the Xbox 360 screen, but it simply won't load the home screen. I wanted to see if I had the option to recover my gamer tag to see if I could retrieve any of the info lost bc I had already beat the game with one character and was close with the second. I hope somehow this can be fixed because I will be furious if all that work just disappears.