Breathing issues

Hello all. I was recently diagnosed with peritoneal cancer which originated as ovarian cancer in my omentum.  In addition I have been dealing with ascites,  blood clots in my lung and moderate plural effusion in my left lung.  My oncologist says these are all related. I have completed 2 rounds of chemo, and my question is about breathing issues.  I have  had fluid removed from my abdomen, but find myself gasping to catch my breath from the simplest task.  I have a few good days, but most days I cannot even stand long enough to brush my teeth without resting. Does anyone else have this problem?