I'm sorry you're still in so much pain.
Please keep using the walker, because it will give you more support. There's no need to rush into using the cane.
Your knee had major surgery, with some additional complications and more work done on it during surgery, so it's only natural that it needs more time to recover. I think it would benefit from a break from PT and more time spent resting, icing and elevating it. That might also help to decrease your pain.
After all, it's less than 3 weeks since you had this major surgery and your knee is still upset from all that trauma.
I'm really sorry about your family situation but, honestly, you need to think about how best to care for your poor knee. Right now, you need support too, not to be the one doing the supporting.
Have you tried combining Tylenol with the Tramadol? That works very well for pain relief.
Here are a couple of charts that Josephine designed. The first one is for 4-hourly dosing and the second one is for 6-hourly:
You need to make sure that you keep within the safe daily dose of Tylenol, which is 4,000 mg in each 24 hours. Check to see if there is any Tylenol (Acetaminophen/Paracetamol) in any other medications you are taking. If there is, cut back one or two of your Tylenol doses, so you stay within that safe 4,000 mg limit.
I'm glad you came back to posting again. We're here to help you and to listen when you need a virtual shoulder to cry on.