Game build taking days?

So I'm currently working on a project for uni which is literally due tomorrow. We had to create an island in Unity then build it and send it to our lecturer.

(To give you some context to this; We're all first year artists and designers. None of us code or anything like that and we've never used unity before. I'm still not entirely sure what half of the stuff in it means as our lecturer showed us nothing.)

Since yesterday afternoon my island has been building. When I went to bed, it was at 5/11 clustering, 12 jobs. 6 hours later, I come and check it expecting it to be finished or at least almost there, and I find that it's only 7/11 Light Transport, 116 jobs.

Because my project is due tomorrow, I don't want to risk cancelling it and having this immense wait all over again, so I'm hoping that by the end of today it will have finished, but can anyone give me any advice for speeding up this process in the future? I had no idea it was going to take so long and it's really stressful knowing that I'm on a time limit to get this sent in.

Thanks very much and sorry for the babbling.