How to merge pictures in Photoshop without losing quality?

Question

Adobe Photoshop

Recently, I became interested in Photoshop and tried to make one image from several pictures, it seemed to work out well, but the quality of the picture fell, the resolution of the picture is FullHD.
- this is what it was, and this is what I did:

Answer 1

Don't export to jpeg or adjust the compression option.