Hello Ms K,
Best not to panic and get all the information first before worrying about any particular condition.
1) Find out exactly what the low oxygen test was all about. "L18" doesn't mean anything to me, but maybe you have it written down somewhere. If you have a condition that causes your oxygen level to be low, you should work with a doctor to get it diagnosed. MS does not affect oxygen.
2) MS is a neurologic condition that is diagnosed based on multiple episodes and findings on MRI, neither of which sound like they are the case.
3) Try to stay put and get things straightened out a bit before flying all these different places. Talk to the ER doc, if he is still there, by telephone and ask him/her what to do next, because they have already seen you and have some idea of what the best diagnosis is at this point.
4) Buy a relaxation CD and use it to calm down while you wait for results and gather information.
--Dr. Sun
