Wake up issues

So I need some help regarding my Mac and it's driving me mad! Its a bit tempermental and it isnt always the same occurance each time, but basically symptons are (somtimes it occurs, sometimes not with each one!):

Turning on It will freeze on white screen (no logo)

upon waking up from sleep it will display black screen with mouse and notifications. no login UI or wallpaper. Can SOMETIMES login if i just type password (as if login screen is still there). mouse dissapears once typing begins

Sometimes when the previous event occurs (^) and i put computer to sleep it will then do the opposite and display just the wallpaper with no input from mouse, keyboard

I have tried removing all devices (webcam, USB mouse etc) and turning on computer but as its tempermental, it may work anyway!

I have also reinstalled a new OS X over the top from internet recovery

Also reformated HDD and restored OS X.

Also reset SMC and NVRAM.

I can not afford to start fresh, i have a 110GB iTunes Library with 210 iOS apps and photos too important to me to be forgotten.

If there is anything I can do otherthan to pay like £80 to hand over my computer to Genius ?? (dont want those peeps looking at my computer)