My eldest girls slept through from 4 months even though they were breastfed, my youngest has been on the formula for 7 weeks and is now 8mths old, she still wakes through the night, I can't do controlled crying, it disturbs her sisters too much and as my husband works shifts he is regularly away when I need support to do it, I also don't like the idea of it although I know plenty of friends who swear by it.
My mum and mother in law both had this problem and both said they held us with no eye contact and carried on reading their book or sat quielty until we calmed down and then went to just a hand on stomach to reassure and then just being in the room doing something else, no attention just there and then to popping in and out until settled. Also give a comforter and make sure you cuddle it with your baby so that it smelss of you to reassure them when you are not there. It has worked with all my daughters but make sure you have duplicates and cuddle the spare when not in use so it is accepted!
I had a dummy as a baby my mother in law didn't agree with them, they have very different ideas on parenting and I thought it very strange they actually agreed with each other on this so I've been trying it for the last 3 weeks, I'm now just popping in and out and she seems to be getting used to settling herself, even with a perforated ear drum and cold! She made more fuss when I tried picing her up last night.
Hope it all goes well with your exams