You may have to make your pics smaller. Here is how you would post. Hit Additional options just under the box your are typing in just under it on left side. Then hit attach and it will let you select pictures from your computer or phone, If you want more than one picture push "More attachments" and you will be able to add from your computer the same as you did the first time. You are allowed up to 4 pictures.
Second picture shows how to resize using Paint on any Windows based computer, be sure to save the image as an .jpg file or other supported file. If you do not know how to access pain in bottom left hand corner of PC there is a box you can type in, type Paint and paint will come up and you select that and do as I showed above and then save it. Be sure you do not rename it the same as the image you resized, I usually ad 2.0 to the title so I know which is the new one.
Every image I have ever shared for someone has had to have one of these things done, every one.