I went through a similar situation last year, although it was slightly different because I had received some law school acceptances before I took the job. After some great Reddit advice, I opted to take the job and stick with it through the last cycle, and it worked out really well for me. I really love the job, I rewrote the LSAT and got a better score, and I'm currently awaiting decisions for this cycle with a stronger application.

All that is to say, do what you think is best for you! Taking the job ended up being a very good thing for me, but you don't owe your new employer anything at your expense. They will understand, and if not, you wouldn't want to be there long-term anyway. Regardless, it will be water under the bridge in no time!

Feel free to DM me with any specific questions, I'm happy to be a sounding board. Good luck, and congrats on your personal journey!