Hugs to you! I didn't have the numbness, but so much of the rest sounds SO familiar. Someone on here should be able to give you more specific advice.

My tiny tidbits are...

Rest as much as possible! If you're able to do the withdrawal thing, I'd say go for it. It allows your body to recover and life to get closer to "normal".

Admit when you need something, and accept it from those who are willing to give it. Try to find someone you can talk to.

Also, while it's true that an MRI usually doesn't show a concussion, it can bring peace of mind. If it doesn't show problems, that's wonderful! If it does show problems, then you will be able to work more effectively towards your recovery.

With your flu "feeling" and dizziness - is it possible that you have allergies or sinus problems? Sometimes the concussion symptoms can mask the symptoms that normally alert you to such problems.

I know this isn't all that helpful, but I just wanted to let you know that you're not alone in this, and it DOES get better.