i can send you some things for classics! i have a lot of resources provided by my school (critics, sample essays, context, etc) as well as a whole copy of my teacher's notes on bacchae! they'd all have to be sent over email though, so if you send me a message i can definitely send those on
definitely also look at jstor, there's a heap of essays on there to do with anything classics. i'd also recommend the omnibus! it's a magazine by the classical association that has an assortment of essays, of sorts, to do with all sorts of classical things - including absolutely loads of the texts we study! you can order previous issues of it for free, as long as you pay shipping.
also, read around the subject - read the other famous plays (poet & the women, medea, antigone, hippolytus, etc) as well as whichever world of the hero text you don't study. it's very useful and well regarded by the examiners if you can demonstrate this knowledge (or at least pretend to have it!) - e.g., the ending lines of bacchae are used in 4 other plays by euripides, which can be used to demonstrate the overarching themes of greek drama; talking about the half-aristeia present in odyssey and how it's reflective of the changing attitudes towards war between the iliad and odyssey being written down by homer