I know how you feel. Mine is financial. Every time I make positive changes to start saving for a goal something happens and sets us back. I managed to save uo $300 and then DS destroyed my phone so had to replace it, even though it had insurance. I am returning to work extra days soon to try and get ahead, but then because DH got made redundant last year and now is working a really sh*tty casual job, his sh*tty pay fluctuates so I doubt the extra days will mean that there is much extra money to save. But I'm determined to keep trying! Sometimes it feels like we're never getting anywhe financially.
I'm Sorry about your knee.
it really does suck but don't give up!