Glad you have come back to this post, please tell us where your op was done, and where you are based, and was the op done through Streamline? It is important to include that info, hard to offer suggestions without knowing where you are.
I am glad you have an appointment next week. I find it hard to believe anyone could fail to be concerned to hear you say you have no feeling in your legs, which clearly indicates a problem, whether due to the surgery or not. Are you able to walk, dress yourself etc. if that is the case?
I do sympathise very much, constant nausea and vomiting is horrible and as you say, makes it so hard to get your fluid in. Are you taking an anti-acid tablet, because I was prescribed these when nauseaus, in order to deal with inflamation, and there is also nausea medication which can be bought over the counter, or prescribed by your GP.
If not, please go back to your GP before the sugical appointment, and ask for some prescription for the nausea. I do not know if you are in the UK, but there are some good travel tablets that do not cause tiredness that can be safely taken, so the GP will easily be able to find something even if you are on other medication.
It may be the case that your pouch inlet is too tight, and needs stretching, but hopefully the surgeon will resolve this for you.
Please let us know how things go on for you, and I am sorry not to be of more help. xx