So recently I've gone out of state and had started sending my significant other pictures and short videos. However I was finding that 75% of them were not going through at all. I tried enabling all sorts of things on my phone and on her phone, as well as multiple restarts and even soft resetting it, but I finally figured out the problem.
For whatever reason attaching pics or vids using the little paperclip symbol in the texting options doesn't work very well. I assume this is a bug or something specifically wrong with my phone, but I figure I'd post this just in case anyone else was having the same issue. If you want to send a picture or a video use the share option by holding your finger on said content until the drop down menu appears. Select "share" and then enter the name of the recipient. Seems to have solved the problem.