Suggest Remedy For Vomiting And Contipation

Hello. Tonight is my 3rd week in mtx. Every week I have been sick with violent vomiting for 3 days after. I also have major constipation. I do not normally have any constipation problems as I have SOD & normally take medicine to stop my stool. I have drank mirilax for days, tried suppositories. Nothing moves out, just the melted suppositotry. I am a thin woman & look 6 months pregnant all the way to ny lungs & my stomach is hard. Is there anything else I can do? Is this normal? It is painful, but I'm on pain meds, so I'm not feeling full effect. Thank you