I'm in 3rd year Honours Life Science and I'd like to see an academic advisor to talk about 4th year courses as well as post-grad and career options. I'm (supposed to be) graduating next year and I have no idea about what I'm doing/what to do. I still haven't found what I'd like/want to do, so I want to know what options are available to me given what I have so far.

I recall that there was some academic/career guidance office in MUSC, but I think that's only for first years. Where should I go to?

You do it through the science faculty. For career stuff you'd see SCCE, and for academic advising you book an appointment with an advisor. If you go to the science faculty website, all the information is there.