Do I need a tutor or a different way of studying?

I’ve been studying for about two months now (~15 mins a day during the week on top of a 60+ hour/week job), and my practice tests are for the most part consistently in the high 160s with blind review in the high 170s, but today I just scored an all time low 163 despite having a perfect score on one section (the third). I’ve gotten perfect scores on both LR and RC sections several times both as part of the test and as one-off. But I can’t break the 170 barrier on a timed test, usually with one very strong LR section and two ~-5ish LR/RC sections. I would like to take the test in September and October then be done but having a 170+ and ideally in the 172-174 range is non negotiable for me to submit an application next cycle. Any advice on the best strategy to reach my goals? I am open to tutoring but have limited time and flexibility in my schedule due to my job.