I'm getting around 30 marks in SNAP mocks, I doubt I would be able to push to 40+ on the D-day. Any suggestions?

see your marks section wise. see your accuracy. focus on areas of improvement. is it speed or accuracy you are lacking. go for solving things you know first in mocks instead of attempting in chronological order. glancing wholly will waste your 5 mins but will increase marks by 10 possibly.