Hello There and welcome to HCM
Firstly there are few things which are needed to be clarified i.e.
1. You've mentioned that you landed on your back and and also hit your head--so was there a CT-Head done or just the X-Ray of the back??
2. From what height did you fell down (was it all the way through / just a few steps)??
3.What all medications are you on and swiched over to what??
4. Few questions regarding the vomit--How frequently are you vomiting/How much quantity/beforefood/after food/what relieves it (it can't be continuous otherwise you would've been probably been hospitalised)--so some thing must have been relieving it(it can be some medicine or something else)
5. Finally are you having any other problems along with the vomiting(any headache/blurring of vision/dizziness/problem in hearing/sleepiness etc.)
If you haven't done any
CT Scan of the Head yet , its better to check in to your nearest ER and get it done and also you need to have a neurologist's opinion regarding this too and its better not to wait any longer since its already been a while .
Get back to me with these details and once again thanks a lot for contacting HCM, Happy to help