Constipation nightmare SOS

As a child I always remember being constipated. Like all the time. My poor parents took me to the ER at least three times a year from 7-14 for doctors to tell them I was full of shit. Literally. As I’ve gotten older my body I guess has adjusted to such a lifestyle and I only go about 3 times a week at the most. HOWEVER the further I get into my pregnancy, the more I can’t afford there to not be room in there for my baby girl. I have been up ALL night double over in pain. I finally made myself get up and go get milk of magnesia and even bought an enema if it doesn’t work. My question to you ladies is what do you use for constipation?? Is anyone else having such a hard time? I’m already so right as she gets bigger and bigger and I can’t keep having nights like this