There are many ways to "glitch" an image, but to achieve what you want (the jpeg artifacting / loss of quality) all you need is time (or a script!).
There are numerous examples online showing deterioration of jpg files by exporting it excessive amount of times. Exporting is the key factor here. This way you are not just saving a copy of the image, but applying the jpeg compression each time. This is very important! You can open and save a copy of a jpeg infinite amount of times without any loss of quality, as the image is not compressed at each save. Only if you apply the compression the image will "age." Here's a video showing an example of how this would work over 1000 iterations.
You can do what that video does easily in any raster graphics program (it would just take time, unless you can batch it somehow). I would recommend using an older program, because, chances are, that new software might have some anti-artifacting algorithms in place (it's a small chance, but better not risk it if you will open sand export 1k times by hand :P). Also, using a lower resolution image will yield better effects. Here's a step-by-step guide to jpeg glitching, using jpeg2000.
The benefit of such approach is that you have total control over how the image is processed and you can introduce other variables to the process (e.g rotating the image 90 degrees each time).
If you would rather have it done fast (and don't have the skills to write a script to do it for you), you can use some ready made web generators. They give you less control over outcome than doing it all by hand, but are definitely faster.
Here's some quick examples from generators I found (the original photo resolution is quite high, you will get more artifacting if you lower the resolution of your photo):
100 repetitions at 0.1 quality
100 repetitions at 0.2 quality. Accidentally turned brightness to -10, other effects at 0