iPhone deleted all 20,000 of my photos itself :(

Hi,

A little Christmas disaster happened to me today; my iPhone 6 Plus deleted ALL 20,000+ of my photos. This was exactly 45 gb worth of photos. I restarted a few times and still nothing. My phone restarts randomly and has done that at least 10 times today. I noticed my photos were gone about an hour ago, after they began restoring. My photos crashed and all my photos were gone. They're still taking space in memory and still showing up as 45 gb of photos. The only thing I can think that is affecting my phone is that I dropped it on concrete a few months ago and the volume down button was dented in. Screen and everything else is in perfect condition and never gave me any problems until today. I did back it up maybe a month ago. Please don't blame me for not backing it up often, I don't expect a usually reliable phone to delete all my photos. is this normal? Is there any I can do until tomorrow? i suppose I could restore from backup but all my photos from this last month and data would be lost. What could be the reason for this? Thanks in advance and happy holidays

edit: I do have AppleCare plus but I don't want a replacement phone. I just hope to get my photos back.