A scare last night

I was diagnosed as soon as I became pregnant because of testing that was done a month or two prior. I take insulin at night and in the AM. I am 25 weeks and for the most part, my numbers have been under control. Last night around 1am I woke up feeling really awful. Really sweaty, shaky and dizzy. I tested my blood sugar and it was 67. I've read anything below 70 is dangerous. I'm just wondering if anyone in a similar situation has experienced these lows before. It really scared me. I had some juice and started to feel better but it scares me knowing this might be happening while I'm sleeping. I have a doctors appointment tomorrow so will talk about this, but wanted feedback from others in a similar situation. Thanks in advance!