This may seem like a cop-out, but you are able to apply for a remission of debt! Except I'm not sure how it works in your faculty, however in mine, the faculty is willing to accept documentation that explains special circumstances that can remove your N grade from your transcript and/or have the fees removed from your HECS debt. If you have any documentation, which may be hard to get in terms of illness as I believe it is illegal to get medical certificates in retrospect/backdated? My faculty does allow for statutory declarations as well, so check if yours does too, and maybe if you do have a previous medical certificate you can attach that. You seem to have extenuating circumstances that explains your performance, so this should be a viable option for you, regardless of whether you can still get into honours with a few fails! However, there have been changes, at least in my faculty, as to when you can apply for remission of debt, so I'd get on this ASAP!