Hi! Worked in general student affairs related to yours (it's not specific for anonymity reasons) and I'd highly recommend applying for an intermission if your medical condition persists since you might not want to tarnish your results which would work against you if you want to enter med. What you can do now (since it's before the census date) is to withdraw from your engineering units and continue with commerce, and then apply for a mid-year transfer.
You might not want to waste your time with 1 subject this semester, but given the fact that you might not be able to enrol in other units anymore (due date was 15th of March), it could be your only viable choice (if you don't want to waste your WAM on Engineering). For a successful course transfer you have to complete 2 units, however, so you might want to continue with 1 eng and 1 comm unit and transfer during mid-year to science. Don't worry about not completing your science degree within 3-4 years since there are a variety of summer and winter units available to you.
There are a variety of Engineering workshops that'll help you at least pass the eng unit you might be doing (just don't do ENG1003 or 1005 and you'll be fine tbh) in the Hargrave-Andrew Library, you might wanna check them out (workshops include Back-on-Track sessions, to get you back on track obviously, academic writing and peer-assisted learning for ENG1001, 1002 and 1003). Of course, email your lecturers and tutors regarding your extraneous circumstances and they should be able to help you out. I'm so sorry for what you have gone through, and all the best!