Everyone the game is not that difficult, but you have to play it a certain way. Basically you want to complete all the side characters before doing any of the main characters as the side characters will either restore their mind barrier over time or cause events where they question the weird activity costing you money to fix it.
So basically do this:
Gain some money to afford the app by doing the city corruption ones (blue border). (don't do prostitution for the main family or one of the endings won't be available). This will lower the towns decency rating and once your phone goes yellow stop doing the money ones and do some of the ones with the yellow border to restore the decency rating back to normal.
You don't need a lot of money to start, around 400 should be safe enough for the first month. Use that money to get Ultra Cool Biz so you can head into the city and basically get all the ones on discount that have a character portrait on them. Meet with them and try to fully corrupt them as soon as possible. When they are fully corrupted they give you 100 at the start of every month. See where I'm getting at?
As you continue to corrupt more side characters the monthly income goes crazy high after four months if done right you should make enough to coast through the rest of the game. The more apps you have active the more effective the lowering of their mind barrier is but I don't recommend getting all the apps unless you have most side character by then.
ALSO REMEMBER: Every event has three variants, normal, lewd, corrupted and pregnant (preg only in post game gallery). Orange is above 50 mind barrier. Red it below 50 mind barrier. Doing pink border events are useless as they are fully corrupted, save it for the gallery later or do it sparingly. Prostitution with side characters won't lower their mind barrier, the purpose of those events are to make 100 money and they don't affect the decency rating of the city.
Then its gg from there as corrupting the main family won't trigger any events (as the side characters are fully corrupted) and it only takes 2-3 lewd events to fully corrupt them. Then you can either have fun watching events or skip to the last week, watch the ending and have full gallery unlock. I suggest saving on the ending selection so you can come back whenever.