Adding multiple images in pages

I'm doing something that should be really easy, but has turned into a frustrating nightmare. I've written a long text and am adding an appendix to the end with photos. Simple, right? No. I went wrong right from the start and added a picture gallery for each picture. Then I added a caption to each of the pictures. Everything looked great. Then I noticed that I had forgotten to add the two first pictures. No big deal, just add them in front of all the other pictures, right? No. A total nightmare.

The pictures don't move forward as one could imagine, but instead they pile up on top of each other and sometimes jump around totally randomly. It is impossible to place the cursor anywhere but before the first picture or after the last one. What if I need to add one more picture before the 7th and the 8th ones? When I go to the settings of the individual pictures, sometimes "move with text" can be selected and sometimes it's greyed out. If I try to drag the pictures forward in the document everything again becomes a mess. What if I add some more text and the photos need to move a couple of pages forward, and they will just pile on top of each other?

Since I most likely will have to remove all the photos and start all over again, what is the "right" way to do this? It's a very simple task: to place a couple of dozen of pictures in the end of a text document, two per page and for them to move forward or backwards if needed. Originally, I used the photo gallery option because it is so convenient to add captions with it (no need to create a separate objects, God only knows how much pita that could create). All help appreciated, thanks! Should not be this difficult.