The newer PhotoShop has Photomerge:
Search “Photomerge”, at Adobe here:
https://www.adobe.com/products/photoshop/family/
Here’s the first one from the search.
https://livedocs.adobe.com/en_US/Photoshop/10.0/help.html?content=WSfd1234e1c4b69f30ea53e41001031ab64-75e7.html
I got a free version of Cannon’s photostitch, do you have a CD that came with an old camera?
Or Goggle “photo stitch” or “photo panorama software”.
This looked interesting, Autostitch, there’s a demo version that times out, I don’t know if its water marked or not:
https://www.cs.ubc.ca/~mbrown/autostitch/autostitch.html#autostitch