Hi and welcome to our little MS community,
Could you please brake up your posts into smaller text blocks in your future posts, people with MS commonly have visual and or cognitive issues that makes reading large text blocks difficult to read....ta :D
I'm a little confused sorry.....earlier this month (August 2016) you had chickenpox, but a few days after recovering from the chickenpox you woke up with bilateral paresthesia -pins and needles in both feet, which traveled up your body to include your lower abdomen and back.
Your family doctor thought the pins and needles was non-specific and probably anxiety related so mum took you to the ER, they initially couldn't work out what was wrong, but at the follow up appt 5 days later you were told it was post viral and admitted you to hospital(?)....9 days stay in hospital and lots of tests, then told they were pretty sure you had MS but just sent you home with 5 days of oral steroids??
I'm very sorry for what you've experienced (hugs) it's an unusual situation for sure, you've had an awful lot happening in only one month....i'm not totally sure if you have been officially diagnosed or if the reason your neurologist sent you home with only oral steroids is because the younger you are the more complicated MS is to diagnose, you might need additional diagnostic evidence before your neurologist will be confident it is MS.
At 16, if you are officially diagnosed with MS, you'll more likely fall with in the category of 'pediatric MS', the Optic Neuritis (which could of been the first MS attack) happened when you were 10-11yrs old and your still under 18. Children can experience more frequent relapses but generally with relapses, if after a relapse you continue experiencing the symptoms or they worse or they return shortly after steroids within 30-45 days, it's typically not a new relapse but the same relapse...
Due to these completely new symptoms happening just after finishing the steroids, it's possibly the rebound effect of steroids and you are still experiencing the same relapse. Although i'm not really sure what could of been the cause the "very bruised, tender feeling all over my body", MS typically doesn't cause symptoms to be all over, it might be a reaction to the steroids but as you continued to develop new symptoms (unilateral hand spasm, face and leg, with additional speech issues) i would highly recommend you consider finding the best MS pediatric specialising neurologist to discuss disease modifying drugs and other treatment options!
Please try not to get overly anxious or self conscious, it actually can make things a lot harder to cope with, it often helps to talk to therapist about everything when newly diagnosed....please consider contacting your local MS society and ask for help in learning how to cope with everything, it honestly will help you through out your life to learn coping skills early, they should be able to get you in contact with some young MSers or a youth support group, worth making a call to see what the MS society can do for you!
Hope that helps, hugs.......JJ