My ipod Classic 160GB freezes and resets itself

I've had my iPod Classic 160GB for 3 years now and has been fine up till october last year when it froze and wouldn't turn back on unless connected to a charger plugged into the wall. I had to then restore it on iTunes which obviously deleted all music off the iPod. I've also reset it before and followed all the steps to fix it from the Apple support website. It has been fine from that point on until last week when i was listening to it and it froze when I went to unlock the iPod to change the song and it turned off and reset itself and took 20 minutes to come back to life. When this happened, I found that all my music which I had put back on since the last time I restored it had been wiped off. it now freezes when connected to my laptop and resets by itself and isn't detected by iTunes. I don't know what else I can do to fix it by myself without having to pay to call apple. Any ideas??