The game has been made significantly easier for v2.2.3. The starting amount of money should allow you to make mistakes and still turn a profit.
1 thorn of rebellion is enough to be obeyed for 80% of non-sexual lessons, it isn't bad.
Your slave has barely anything in awareness, taming and devotion.
Important to note, her mood is very low. Hard to get her to listen well during lessons.
Her traits and stats might also not been the best for you to make a quick buck.
ImperatorAugustus manages a 0 start with Johny in hard obedience difficulty. We'll never release a version in which it is not possible, and there needs to be several viable strategies.
So this shows you that you have room for progression, and strategies to invent and try out
Have you read and completed the tutorial for all three characters in v2.2.3 yet?
I wonder which changes exactly.
It wouldn't help if you claim: "the changes that made the game harder than v1.7 or v1.2.1", because we never aimed to make it harder than those, just more realistic. Maybe it is harder, by accident. But some things have been made objectively easier since (the fact you don't need to pay a nutritionist if you or your assistant can fit that role, or the obedience thresholds for cleaning on most slaves, etc.)