A little upset

I went to the doctor today. I am 13+6 and have been throwing up daily since week 7. I have lost 13 lbs so far.  I had told her before that my nausea and throwing up was getting out of hand but I feel like she kind of brushed it off. Today I see her and she's like,  omg I want to admit you to the hospital and put a picc line in (like a feeding tube). She wants a nurse to come to my house every other day to administer fluids and what not. I begged her to give me a chance to gain weight on my own because I REALLY don't want a picc line. She just now gave me Zofran and told me to drink boost 2x/day. I have to go back in one week and if I haven't gained enough I have to get the picc line. Do you guys have any advice on how to gain weight? Most days I can't even keep down water.