Animated GIF of enema bag giong dry

I recently purchased a new camera, not that I don't have enough cameras. It is a DJI Pocket Osmo 2. What's unique is that it is fairly small and has a stabilizing gimbal, similar to what is on a typical drone.

On Xmas morning, I deserved a good enema. I normally do two three quart coffee enemas a week, but this time I took four quars of coffee. I really took my time, and as the one gallon clear silicon rubber Klystra bag emptied, I do a photo every few minutes, a total of 20 photos, each about 1MB shot in jpeg.

I'd like to make an animated GIF of the enema bag going dry. I'm not an expert of creating animated GIFs and could use some help/advice. I use Photoshop which has the capability of creating the files but instructions I've found on YouTube are not too clear., One of the problems is that it may have taken 10 minutes to complete the fill, at 30 frames per second, the picture is gone in a flash, the 20 frames need to be properly manipulated.

If this works out perhaps I could make some more like belly distensions, or who knows what. I could use some ideas/help

TIA the hoseman