I’m sorry to say that your horse has bolted.
As you have taken your case to a court already and had a a ruling, you’ll need to find some compelling ground to have it reviewed in a higher court.
Be mindful that taking your case to an appeal does not allow you to enter new evidence.
This is the pitfall of self representing. (I’m not suggesting that self representation is a bad idea, but not having a lawyer guide you risks falling into the traps of the legal system. Again to save any argument, I believe the legal system we have is equitable, though to the lay person somewhat baffling).
For others reading this, ALWAYS consider mediation rather than court. In mediation no one assumes blame, and if you can come to an agreement, the amount you get in your pocket can be greater than that awarded in a court less your costs. Most lawyers will help you with mediation at a a low cost.
Court is also risky and you may not get the result you want.
As this member has found, sometimes the cost of legal action exceeds your losses. It’s a call whether you want to be right ( and spend lots of money proving it) or sometimes just accepting defeat and cutting one’s losses.