My most recent pictures don't show up when I try to post to social media

[Nicolio73084]

If I try to share a picture to my post on facebook or add pics to my album, or even on Instagram, when it pulls up my gallery it is no longer showing my most recent pictures. It will show like the last 4 pictures I have taken and then the rest are in some weird order, like any collages I have made, then all my videos, then Snapchat pics I have saved. It just started doing this a few days ago and I can't figure out why. I have a Note 5 and can't find anything to tell me how to fix it.