1. There's career connect, in campus centre, right across from monash connect. They have (or at least did last year - verify this) 10 minute drop-in sessions, or 30 mins by appointment.
2. If your health (either physical or mental) won't allow you to do well this semester, your best course of action is probably to unenrol from your subjects and defer / take intermission (I don't know which one it would count as, but it doesn't really matter). Yes, sticking it through might be more tempting (rather than 'giving up'), but it sounds like you need the time to firstly get better, and secondly figure out what you want to do at uni (or outside of it). It's much better that you take this time, rather than commit to something that you don't want to do and/or can't do. Also, if you apply for transfer, whether internally or externally, they likely will look at your marks from this semester. So to me it sounds like unenrolling, at least for now, is the better option.
3. Many people who do law realise that they don't want to become lawyers. But if you have zero interest in the subject matter - what the law is, how to apply it, why is it as it is - then it mightn't be the degree for you. Keep in mind that first-year law probably isn't the best guide to what the rest of your degree will be like - most people don't even really figure out how to approach it till second year at least, and FOL is a bit of a standalone (though if you're finding it boring, it might mean that you won't find the rest of the degree too interesting).
4. Finding people you enjoy spending time with at uni can be tough, but it's doable. Have you tried speaking to people in your tutorials? Also, some events (not the big parties etc) shouldn't be too bad to attend by yourself. Are there any clubs that really speak to your personal interests? You can always shoot them an email asking about what semester 1 events they have.
5. With regards to the Arts side, while I've never done an arts degree, it's extremely diverse. You might not enjoy psych, but there's plenty of other areas, of course. Why did you pick arts in the first place? What are you personally passionate about?