Mate, with just 250mg Sustanon a month. Your high isn't going to be very high.
You'll probably have a week where you feel relatively normal, and then you'll gradually tire and fatigue from about week 2 onwards.
But you NEED to relay these feelings to your GP, keep a diary if possible - a good doctor won't go by blood tests alone, he will listen to his patient and work with them to improve symptoms. Remember, this will be new ground for him too. It's important you talk to him about half lives, peaks, troughs, estrogen etc - to make him realise that you are educating yourself with your ailments.
Only by doing this, will he drop your injection frequency, and only when he's done that will he consider trying other options.
Please stop panicking - you are just going to have to play the game.