Ladies I'm only 8 weeks and feel like sick.

I have issues with severe constipation. The doctor told me to take miralax. I did last night. Things are starting to move along but very slowly. I feel shakey, starved and like I'm going to be sick or pass out. I keep trying to eat little by little to try and satisfy the feeling but I feel like death. I doubt there is anything the doctor can do and they said no to an enema. Is there anything safe during pregnancy that'll work more quickly to help empty my stomach? Is there anything I should be eating that may be helpful?