Starry what a awful feeling to have. Chaffinch is right when she says the HG amplifies everything. I had to have my medication increased to handle the increased anxiety and lows I was having. At 12 weeks I point blank refused to get on a bus and DH had to drive me the 5 minutes to the hospital which he didn't at all mind but still I felt ridiculous. I struggle with being out in public which got 100% worse after pg and hg.
Not being in control of our bodies and not being able to enjoy food and drink and having to spend 90% of the time in the loo or prostate on the sofa gets the best of people down! When you have something on top of that it's a real battle but you will get through and it will be worth it :) It will stop soon, mine started easing up around 15 weeks or so. It's there, but much better than before.
My only miracle cure was icy icy cold tap diet coke which gave me a bit of energy and halted the sickness for a few hours but that also had downsides as we aren't supposed to have too much caffeine are we! But it got me through my final few weeks at work and the baby is fine. You could try sipping on one whilst you walk (I did that a few times when I had to go out with the dog). You can have something like 5 cans of coke a day and lucinda has recommended flat coke before. You could just put a straw in a can and sip and stroll. The caffeine should give you a boost to get through the hours.
It should ease off soon and please do go and talk through things with your GP or midwife if you aren't keeping any food down. Good that you are seeing midwife tomorrow, do tell her all and they should be able to help with coping mechanisms and keep an eye on your nutrition. Don't be fobbed off!
Can you cope with sucking sweets at all? Can you cope with a taxi or too bad with your condition? I found barley sugars helped lots but others find sour sweets/Skittles etc all help. I got addicted to fruit Mentoes for a while as well.
Am sure the scan will be brilliant. I was in floods of tears in the waiting room and then front of my consultant at that same point as I was convinced all was terrible (long story), who immediately whipped me in to have a look and reassured me all was ok. It's a magical sight seeing your baby and I think you'll find the journey home so wonderful as you'll be buoyed up by the sight of your little one.
Are you going on your own or is your DH/DP/mum/friend going with you too? It might help to have someone to support you too. The one time I went for a scan on my own I was a total mess so DH was under orders to never let it happen again!
Let us know how you get on, hugs.