Second HG pregnancy

So I had HG during my pregnancy with my daughter who is now 3 and I unexpectedly found out I'm pregnant with baby number 2! I'm excited to be a mama again but I'm only 7 weeks and have already been in the hospital for 6 days with sever dehydration, abnormal liver functions, and dangerously low potassium levels. The Dr sent me home on Zofran and protonix and it's not helping. Why does this time seem so much harder sooner?!