If your having trouble. There's a couple cheats on gamefaqs.com. The cheats are actually not game breaking where you end up like god-like. Example there's two cheats, one gives you 100,000 but cost 300 points. (i'll explain the points later.) Then there's a cheat that halves the weight of all your item on your ship, that's 60 Points.
Note, the cheat that gives you 100,000-cash replaces how ever much money you have to 100,000. It does not add, so if you have 50,000 and use the cheat, now you have 100,000. Worse, if you have 500,000 and use the cheat, you go back to 100,000. So, you really can't get too rich using the cheat and let me tell you, 100,000 might be alot, but its not. Later in the game, say around year 7-10, there will be ships for sale that are more than 100,000 so you have to earn your cash for those.
Now, the way the point system seems to work is everday you get one point. Say you use the 300 points cheat. You can't use anymore cheat until some time later when you accumulate enough points. So you wait 300 days and accumulate 300 points and decide, I want more cash. Then you realize, I have 70,000 and the cheat would only bring it up to 100,000, so that seems like a waste. You decide you want the 60 point cheat and so you use 60 points. So it seems like you have 240 left, WRONG. When you enter the cheat, it uses up all the points. You could have 5000 points and if you use a cheat, all that is gone.
On the bright side, kinda, you could use the 60 points cheat after 60 days. But you never know cause who knows, you might need that 300 point money cheat in the future since you might end up broke. And if your not, you really don't need to cheat at all.