Sorry that your going through this too, I think for us it's been a bit different as Isla didn't have an allergic reaction but was very sick and generally poorly on normal formula.
I make up six bottles in a morning and put them in the fridge and then just use them as and when needed. In terms of seeing a dietician...... Well three weeks ago they told me they would ring me to go through the next stage of what is happening, I'm yet to hear off anyone! The milk we have got has been given to us on repeat prescription so I think after I have got the next lot I will ring the dietician myself and ask her what I need to do about weaning etc.
How is your lo now?