Lovechild, I see you have 0% tax rates, I suggest setting them up so your money don't slowly deplete.
45% personal tax rate and 100% corporate maximizes income.
Personally I like the slow pace of Project Terra. It aims for "total realism" but I think it's much too fast for that - it's been like 3 months since we started but my population has already quadrupled. Not realistic.
The pace makes it nice to play the game casually over months or years.
I
should I just
Sell 50% of all my resources for money? I'm bad at marketing.
If you want to earn money from the market, place sell offers for the resources you don't need underbidding the best offer (if it's significantly big, and not like 5 or 10 concrete).
At the same time, place buy offers on the same resources to fill your storages again, overbidding the highest buy offer, if there's a significant price difference between the buy and sell offers.
As such it doesn't really matter to me which are my resources and which are from the market. It's all just about selling and buying as many resources as possible, at as big price differencies as possible, while still spending those you need on your own nation.