Aouch... Austria Hungary when no one trusts you. It's gonna be fun. As Austria Hungary, create wars. First, tell Italy your country is a no go, you're just gonna be fighting without ever winning and, so, he should go west. Then, warn France of a potential Italian attack. Suggest Turkey to make an alliance against Russia, meanwhile, inform Russia that Turkey's gonna attack. Then you can go on with ENG-FRA, FRA-GER, ENG-GER.
The main key is to keep them guessing. If they are worried about everything, will they think of attacking you? After the first year, go against either TUR-RUS or ITA (the one that likes you the less). Then, finish him off, go to the person that likes you the less, etc.
You should do okay following this technique.
Btw, what a sick teacher you have! :D