You're meant to have a harder time, as the days pass (so you inevitably will get a run end at some point).
Afterwards, you do the Meta unlocks via the Perk Tree you access at the beginning of each run, to make future runs stronger and go for longer.
As general strat in-run:
- when you start the run, try to normaly only go for the Areas you can decently beat without taking too many turns doing so (if you take too many turns in a fight, you might temporarily get a bit more gold and/or loot, but you'll also rack up addiction at a fast rate).
- Always do encounters in multiples of 3 (each 3rd exploration nets you a Potion from the alchemy lab), preferably 6 per day (meaning 4 fights, 2 labs).
- Visit the City once every 3 days (I think that's how it was) at a minimum, when the Recipe shop opens (it only opens once every X days, I think it was 3), to peruse the wares
- Also whenever you visit the city, don't forget to go to the Inn to do the daily Job, it's extremely easy generally (choose the Addiction you have the lowest in), and nets you decent gold for minimum Lust increase)
- Also also, regarding using the Church to ease addiction, try to use it earlier rather than later (attempting to keep addictions low, but not using the money if you're not already having a decent weapon and accessory already equipped), since prices increase proportional with the Day number