Two things I'll recommend, If you can crop the pics some, crop them. Typically that's all it takes to get any pic deemed "too large" onto a post here. Second suggestion, use a site called "tinypic.com" go to upload and upload any pic from your computer.
When you get to "Resize", I use "Message Board" (640x480) and that always works. Then use "upload now" click on full size pic, and upload to PC and use from PC to forum.
Sounds invollved, but takes less time that it to me to explain here...
IPhone pics are typically too big to post as-is unless you have the photo resolution set to a lower setting than the default high-resolution settings. Resize them to 800x600, or in the future, adjust the photo resolution on your phone to a smaller size before you take the pics. I always have to resize pics before posting them. You can use almost any online photo site, or download a photo editing software.