Way to recover pictures from a water damaged phone with no back up?

I had an iPhone 6 and dropped it in water, and since I didn't have enough storage at the time, I stupidly never backed up my phone to save my pictures. I was SO sad, considering I'd just spent a semester abroad and took a lot of pictures. When I was told I couldn't get them back since I hadn't backed up my phone, I resigned and got myself an iPhone 7, backing it up to my most recent back up date. But one day, I'm scrolling through my pictures when I see about 30 pictures of Paris that I took when I was abroad, all geotagged. They were pictures I had taken with my iPhone 6. A half hour later, poof. They're all gone. Only one remains, a crappy shot of the Eiffel Tower. But it's a picture I myself took, and I'm at a loss. Does anyone have a clue of what happened? Are my pictures still somehow out there in the universe, and is there a way to recover them? I've checked iCloud.com and nothing. Just that one measly picture. I took a screenshot of the pictures that were there for like a half hour before they disappeared, so I'm not crazy. I'm mind boggled by this though. Help?