Help me change my avatar?

I think that image link may be broken. When I clicked that link I couldn't get any image to open.
Try using the "Choose File" button below the URL box to upload the original file from your computer. If you need to resize it you can use tinypic and select to resize it, then save it to your computer.

 

I'm not positive, but I believe you can still upload it to tinypic and resize it even if you're on a phone, then save it to your phone and select to upload that image.

I could be wrong though. I'd give it a try.
If there's any way for you to get a copy of the image posted on this thread, someone here may be able to re-size it for you.

 

Why don't you try saving that picture to your mobile phone and then try uploading it directly? It might work, I'm not sure.