are you using phone pics and then sending to pc to upload or uploading direct from phone.
pain i know but mine are 3-6mg each from phone and only need to be 2-300kb for a decent quality pic.
check app store for Photo Compressor. blue bacground white square and heart top right. its free to download and use.
open app> compress photos> tick to compress then go back to picture folder and there will be two of same pic, use latest pic to upload and job done. 9.47mg into 522kb
ive tried the app to remove original but doesnt seem to want to do that.