Okie so you have 2 problems...
1.Enslavement
2.Loosing Money
For 1: You can set yourself free If
Either ; Your Master sets you free
Or ; You got to be 10 times he`s Pr/Power and then click "Slave Empires" -Click "Declare Independence"
For2:
I assume you`re a terran. I suggest reading through the walkthrough located in the manual, and following the missions.
The jist of it is,
research 20 lvls of commercial,
then build housing, agriculture, and commerical infrastructure on your planets so that you
a. have population to build stuff on your planet (housing)
b. can produce food to sustain your population (agriculture)
c. produce money through commerical/business type infrastrucutre (commerical)
And that`s how you get cash.