Ipad Pro 12.9 first generation stuck on Apple logo

Hello,

over night, my Ipad Pro 1. Generation 12.9 stucks on Apple Logo. The Ipad had given me some signs, weeks before. A few times it suddenly shut down and often when I connected the keyboard it shuts down, but it worked for me. Battery connection very likely lose. Also I watched the new generation of the Ipad Pro 11 for a good price, around the last black friday but there wasnt a good price, so I didnt bought one. :( Now I have the problem. If I had bought the new one, I would have had the Ipad repaired for the battery. (More for sentimental reasons. :D)

My biggest problem is, I need some data from this Ipad for my school. I tried to update it via Itunes but nothing worked. Error 9 and 78. I tried it via 3uTools. I tried it multiple times. I tried it after some days again.

My question is, does anyone has some good solvings for this problem? Does anyone knows, could the Apple repair service update my Ipad without the lost of my data? Or maybe another repair service, like mcrepair.de? Any good recommendation for repair services? (I ask about the Apple service because I want to get the battery replace anyway.) Does some repair service may have some better software?

I hope someone could help me! I just uploaded all my school stuff on this Ipad and got rid of my paper work. :( So this would be very bad for me.

Thanks. :(