Constipated and desperate!

I've been suffering from constipation ever since I was like 5 weeks pregnant and it seems like it's been getting worse over the weeks .. I've tried EVERYTHING !! The doctor told me to take miralax which is a stool softener but I just keep popping hard painful HUGE balls (sorry, tmi) . I'm so scared to poop bc I don't want to push hard enough bc id feel like I would be pushing the baby out . But crap, it hurts like hell and my butt hole ends up bleeding every time! Any suggestions please?!