Nelp me with early game economic problems

I honestly dont know what Im doing wrong. I dont remember having this problem in DA but now that i got TA i seem to be having a lot of problems with economy in the early game. Here is what I do to start:

Explore and try to colonize as many planets around as I can. I often buy a couple colony ships. Then I start to build up planats. I prefer to specialize planets to one thing or another, like one planet will ony have farms, enternainment centers and economy centers, while another will only have production, and another will only have research. Everything goes great at first but at about the time where I get 8 planets or so, I go into a huge pile of economic shit. I am forced to set taxes at 70 or so percent and have to have production capacity at 30 or 40 to not loose money.

I dont know what to do. I could theoretically not take as many planets, but all the other races do. So what is my problem?