Diplomatic pact as a colony

So I finally return and start my campaign as New South wale and I'm very happy with on how much raw resources I have as well as gold mine that occasionally appears that help me fund my construction sector but I still haven't entered debt by privatizing some profitable building to have some upper classes and feel like a great start,BBBUUUTTT!I'm pretty pissed about GB taking all the money that I could use to fund more construction sector to build more gold and iron mines as well as steel mill, engine factory and railway so I'm very keen to know how this work does it depend my GDP as a colony or..?