Firstly, we're sorry to hear that. Frustration is the last emotion we want to conjure when using Picter.
Upload speed can be affected by by many things both at our end or yours.
Please make sure of the following:
You are on a solid broadband connection and if possible plug your computer into your router via ethernet rather than WiFi.
End or pause any activities on your network that might be consuming bandwidth (streaming, online games, uploads or downloads running at the same time in other tabs etc.)
Find more info on file requirements here.
If you're still experiencing issues and would like to contact support, please visit this upload speed test page first (the test will start automatically so just wait for it to finish) and include the results with your issue.