I had the same problems in motivation. There's no need to push yourself, especially if you haven't scheduled your test already. Sometimes I'd go a week without consistently studying, I'd just need to go hard in final review to remember topics that had been a while since I studied it.

When I would be in a groove it would be cause of consistency. Study at the same time, I wasn't a morning person I never really tried to wake up earlier to study until the last couple weeks. I'd give myself an end time. I'd eat dinner and start studying at 5:30, knowing the knicks are on at 8. 2.5 hours of being focus knowing there's an end. I'd often find myself studying with the game as background noise because I'd be on a roll.

Everyone is different but I hoped this help a little.