Plenty options out there - lecturer (as you mentioned edu field), management consultant (entry barriers somehow higher), finance related (banks, IB, financial advisory), risk advisory (internal control related), HR, procurement, startups and a lot more.

Any reasons you claim you are not good in marketing? Prior experience or because of results achieved for marketing subject?

IMO, one cannot decide a career for you, you need to identify what do you like to do or what would you like to try out next as well as the reasons behind causing you to have the idea of leaving the job.

Are you currently in mid-tier / big four? Are the overburden issues due to lack of staff (firm issue), poor allocation of tasks (manager issue), or your own efficiency and capabilities (your issue)? If it's the former, would going to another firm solves the issues? If the latter, perhaps you should reflect and see if you could make improvements (time allocation, reduce distractions, more discussions with managers etc).

Hope my 2 cents could slightly help.