Hi and welcome,
Your question has landed in the MS community and what you are experiencing is NOT associated with neurological conditions like MS, cancer or something serious, what you are describing is suggestive of a common cold or viral infection that your immune system is currently fighting off.
Tell mum or dad you keep feeling lightheaded and your nose has started to become runny now, so they are aware you are not feeling well and you 'may' need to go to the dr for antibiotics if your immune system can't get rid of the bug on it's own over the next week or two...
Hope this helps you stop worrying.....JJ
If you haven’t had a injury then I would like you are dehydrated and it’s causing you syncope.